Transmission Fundamentals

1. What is the opposition to the transfer of energy which is considered the dominant characteristic of a cable or circuit that emanates from its physical structure?

 a. Conductance

 b. Resistance

 c. Reactance

 d. Impedance

2. When load impedance equals to Zo of the line, it means that the load _____ all the power.

 a. reflects

 b. absorbs

 c. attenuates

 d. radiates

3. impedance matching ratio of a coax balun.

 a. 1:4

 b. 4:1

 c. 2:1

 d. 3:2

4. Which stands for dB relative level?

 a. dBrn

 b. dBa

 c. dBr

 d. dBx

5. Standard test tone used for audio measurement.

 a. 800 Hz  b. 300 Hz

 c. 100 Hz

 d. 1000 Hz

6. When VSWR is equal to zero, this means

 a. that no power is applied

 b. that the load is purely resistive

 c. that the load is a pure reactance

 d. that the load is opened

7. ______is the ratio of reflected voltage to the forward travelling voltage.

 a. SWR

 b. VSWR

 c. Reflection coefficient

 d. ISWR

8. Transmission line must be matched to the load to ______.

 a. transfer maximum voltage to the load

 b. transfer maximum power to the load

 c. reduce the load current

 d. transfer maximum current to the load

9. Which indicate the relative energy loss in a capacitor?

 a. Quality factor

 b. Reactive factor

 c. Dissipation factor

 d. Power factor

10. What is the standard test tone?  a. 0 dB

 b. 0 dBW

 c. 0 dBm

 d. 0 dBrn

11. The energy that neither radiated into space nor completely transmitted.

 a. Reflected waves

 b. Captured waves

 c. Incident waves

 d. Standing waves

12. Micron is equal to ______meter.

 a. 10-10

 b. 10-9

 c. 10-6

 d. 10-3

13. 1 Angstrom (A) is equal to ______.

 a. 10-3 micron

 b. 10-10 m

 c. 10-6 micron

 d. 10-6 m

14. Why is it impossible to use a waveguide at low radio frequencies?

 a. Because of the size of the waveguide

 b. Due to severe attenuation

 c. Due to too much radiation

 d. All of these 15. ______is the transmission and reception of information.

 a. Modulation

 b. Communications

 c. Radiation

 d. Emission

16. What is the loss of the circuit in dB if the power ration of output to input is 0.01?

 a. 20

 b. -20

 c. 40

 d. -40

17. Transmission lines are either balanced or unbalanced with respect to

 a. Negative terminal

 b. Reference

 c. Ground

 d. Positive terminal

18. The standing wave ratio is equal to ______if the load is properly matched with the transmission line.

 a. Infinity

 b. 0

 c. -1

 d. 1

19. ______is the advantage of the balanced transmission line compared to unbalanced line.

 a. Low attenuation

 b. Easy installation

 c. Low radiation loss  d. Tensile strength

20. ______is the method of determining the bandwidth of any processing system.

 a. Fourier series

 b. Spectral analysis

 c. Frequency analysis

 d. Bandwidth analysis

21. What causes the attenuation present in a waveguide?

 a. The air dielectric filling the guide

 b. The coating of silver inside

 c. Losses in the conducting walls of the guide

 d. Radiation loss

22. A device that converts a balanced line to an unbalanced line of a transmission line.

 a. Hybrid

 b. Stub

 c. Directional coupler

 d. Balun

23. What is the approximate line impedance of a parallel-strip line spaced 1 cm apart with the length of 50 cm?

 a. 10 ohms

 b. 15 ohms

 c. 18 ohms

 d. 23 ohms

24. What is the average power rating of RG-58 C/u?

 a. 25 W

 b. 50 W  c. 75 W

 d. 200 W

25. A coaxial cable used for high temperatures.

 a. RG-58C

 b. RG-11A

 c. RG-213

 d. RG-211

26. If you have available number of power amplifiers with a gain of 100 each, how many such amplifiers do you need to cascade to give an overall gain of 60dB?

 a. 2

 b. 3

 c. 4

 d. 5

27. You are measuring noise in a voice channel at a -4 dB test point level, the meter reads -73 dBm, convert the reading into dBrnCO.

 a. 12

 b. 16

 c. 18

 d. 21

28. The velocity factor for a transmission line

 a. depends on the dielectric constant of the material used

 b. increases the velocity along the transmission line

 c. is governed by the skin effect

 d. is higher for a solid dielectric than for air

29. Impedance inversion can be obtained by  a. a short-circuited stub

 b. an open-circuited stub

 c. a quarter-wave line

 d. a half-wave line

30. Transmission lines when connected to antennas have

 a. capacitive load

 b. resistive load whose resistance is greater than the characteristic impedance of the line

 c. resistive load whose resistance is less than the characteristic impedance of the line

 d. resistive load at the resonant frequency

31. One of the following is not a bounded media.

 a. Coaxial line

 b. Two-wire line

 c. Waveguide

 d. Ocean

32. The impedance measured at the input of the transmission line when its length is infinite.

 a. Input impedance

 b. Open circuit impedance

 c. Characteristic impedance

 d. Short circuit impedance

33. The following are considered primary line constants except

 a. conductance

 b. resistance

 c. capacitance

 d. complex propagation constant 34. The dielectric constants of materials commonly used in transmission lines range from about

 a. 1.2 to 2.8

 b. 2.8 to 3.5

 c. 3.5 to 5.2

 d. 1.0 to 1.2

35. Typically, the velocity factor (VF) of the materials used in transmission lines range from

 a. 0.6 to 0.9

 b. 0.1 to 0.5

 c. 1.0 to 0.9

 d. 0.6 to 0.8

36. For an air dielectric two-wire line, the minimum characteristic impedance value is

 a. 85 ohms

 b. 85 ohms

 c. 90 ohms

 d. 88 ohms

37. When a quarter-wave section transmission line is terminated by a short circuit and is connected to an RF source at the other end, its input impedance is

 a. inductive

 b. capacitive

 c. resistive

 d. equivalent to a parallel resonant LC circuit

38. A transmitter operating at 30 MHz with 4 W output is connected via 10 m of RG-8A/u cable to an antenna that has an input resistance of 300 ohms. Find the reflection coefficient.

 a. 0.71

 b. 0.77  c. 0.97

 d. 0.76

39. A quarter wave transformer is connected to a parallel wire line in order to match the line to a load of 1000 ohms. The transformer has a characteristic impedance of 316.23 ohms. The distance between centers is 4 inches. What is the percentage reduction in the diameter of the line?

 a. 85%

 b. 83%

 c. 86%

 d. 90%

40. The concept used to make one Smith chart universal is called

 a. ionization

 b. normalization

 c. rationalization

 d. termination

41. What are the basic elements of communications system?

 a. Source, transmission channel, transmitter

 b. Transmitter, receiver, transmission channel

 c. Information, transmission channel, receiver

 d. Sender and receiver

42. ______is the transmission of printed material over telephone lines.

 a. Internet

 b. Data communication

 c. Telegraphy

 d. Facsimile

43. ______is a continuous tone generated by the combination of two frequencies of 350 Hz and 440 Hz used in telephone sets.  a. DC tone

 b. Ringing tone

 c. Dial tone

 d. Call waiting tone

44. ______are unidirectional amplifiers having 20-25 decibel gain that are placed about 75 km apart used to compensate for losses along the telephone line.

 a. VF repeaters

 b. Loading coils

 c. Loop extenders

 d. Echo suppressors

45. ______is a component in the telephone set that has the primary function of interfacing the handset to the local loop.

 a. Resistor

 b. Capacitor

 c. Varistor

 d. Induction coil

46. Pulse dialing has ______rate.

 a. 20 pulses/min

 b. 10 pulses/min

 c. 10 pulses/sec

 d. 80 pulses/sec

47. ______is a telephone wire that connects two central offices.

 a. 2-wire circuit

 b. Trunk line

 c. Leased line  d. Private line

48. The central switching office coordinating element for all cell sites that has cellular processor and a cellular switch. It interfaces with telephone company zone offices, control call processing and handle billing activities.

 a. MTSO

 b. Cell site

 c. PTSN

 d. Trunk line

49. ______in a cellular system performs radio-related functions for cellular site.

 a. Switching system

 b. Base station

 c. Operation and support system

 d. Mobile station

50. A technology used to increase the capacity of a mobile phone system.

 a. Frequency re-use

 b. Cell splitting

 c. TDM

 d. FDM

1. Impedance 18. 1 2. absorbs 19. Low attenuation 3. 4:1 20. Spectral analysis 4. dBr 21. Losses in the conducting walls of the guide 5. 1000 Hz 22. Balun 6. that no power is applied 23. 10 ohms 7. Reflection coefficient 24. 50 W 8. transfer maximum power to the load 25. RG-211 9. Dissipation factor 10. 0 dBm 26. 3 11. Standing waves 27. 21 12. 10-6 28. depends on the dielectric constant of material 13. 10-10 m used 14. Because of the size of the waveguide 29. a quarter-wave line 15. Communications 30. resistive load at the resonant frequency 16. 20 31. Ocean 17. Ground 32. Characteristic impedance 33. complex propagation constant 43. Call waiting tone 34. 1.2 to 2.8 44. VF repeaters 35. 0.6 to 0.9 45. Induction coil 36. 85 ohms 46. 10 pulses/sec 37. equivalent to a parallel resonant LC circuit 47. Trunk line 38. 0.71 48. MTSO 39. 83% 49. Base station 40. normalization 50. Frequency re-use 41. Transmitter, receiver, transmission channel 42. Facsimile

51. If the grade of service of a telephone system indicated P = 0.05, what does it mean?

 a. Completed calls of 5%

 b. Lost calls of 5%

 c. Lost calls of 95%

 d. Lost calls of 105%

52. ______is the Out-of-Band signaling between Toll Central Offices (Bell System Standard).

 a. 3, 825 Hz

 b. 3, 700 Hz

 c. 2, 600 Hz  d. 800 Hz

53. In a telephone system, the customer’s telephone directory numbering is from 000 to 999, what is the capacity of a telephone system numbering from 000 to 999?

 a. 100 lines

 b. 1000 lines

 c. 10, 000 lines

 d. 100, 000 lines

54. If the SWR is infinite, what type of load transmission line has?

 a. Purely reactive

 b. Purely resistive

 c. Purely capacitive

 d. Purely inductive

55. Not more than ______digits make up an international telephone number as recommended by CCITT REC. E. 161.

 a. 8

 b. 10

 c. 11

 d. 12

56. One (1) Erlang is equal to ______.

 a. 360 CCS

 b. 36 CCS

 c. 3.6 CCS

 d. 100 CCS

57. Standard tariff for flat rate telephone service beyond the normal flat rate in that area.

 a. WATS  b. OTLP

 c. TIP

 d. DTWX

58. The standard analog telephone channel bandwidth.

 a. 300-3400 Hz

 b. 1200 Hz

 c. 200-3200 Hz

 d. 300-3000 Hz

59. Type of switching in which a pair of wire from the telephone set terminates in a jack and the switch is supervised by an operator.

 a. Crossbar switching

 b. Manual switching

 c. Electronic switching

 d. Step-by-step switching

60. Every time when the telephone is idle, the handset is in the ______state.

 a. On-hook

 b. Off-hook

 c. Busy

 d. Spare

61. ______is a component in the telephone set that has the primary function of compensating for the local loop length.

 a. Resistor

 b. Varistor

 c. Capacitor

 d. Induction coil 62. What kind of receiver is used in conventional telephone handset?

 a. Carbon

 b. Electromagnetic

 c. Ceramic

 d. Capacitor

63. A voice-grade circuit using the PTN ha an ideal passband of

 a. 0 to 4 Hz

 b. 0 to 4 MHz

 c. 0 to 4 kHz

 d. 0 to 4 GHz

64. ______is the minimum-quality circuit available using the PTN.

 a. Basic voice grade (VG)

 b. Basic voice channel (VC)

 c. Basic voice band (VB)

 d. Basic telephone channel

65. Direct distance dialing (DDD) network is called

 a. Private-line network

 b. PT network

 c. Dial-up network

 d. Trunk network

66. What is the advantage of sidetone?

 a. Transmission efficiency is increased

 b. Speaker increases his voice resulting in a strengthened signal

 c. No dissipation of energy in the balancing network  d. Assure the customer that the telephone is working

67. ______is a special service circuit connecting two private branch exchanges (PBX).

 a. Phantom line

 b. Tie trunk

 c. Tandem trunk

 d. Private line

68. The published rates, regulation, and descriptions governing the provision of communications service for public use.

 a. Toll rate

 b. Tariff

 c. Bulk billing

 d. Detailed billing

69. What is the power loss of a telephone hybrid?

 a. 1 dB

 b. 2 dB

 c. 3 dB

 d. 6 dB

70. Telephone channel has a band-pass characteristic occupying the frequency range of ______.

 a. 300-400 Hz

 b. 300-3400 Hz

 c. 300-3000 Hz

 d. 300-2700 Hz

71. The first Strowger step-by-step switch was used in ______.

 a. 1875

 b. 1890  c. 1897

 d. 1913

72. What is the phase delay of an 800 Hz voice signal if the phase shift is 15 degrees?

 a. 52 μsec

 b. 1.25 μsec

 c. 83.33 μsec

 d. 26 μsec

73. What is the CCITT recommendation for a preparation of loss plan, a variable loss plans and a fixed loss plan?

 a. G. 133

 b. G. 141

 c. G. 132

 d. G. 122

74. What is the diameter of a copper wire to be used in a 16 km loop with a dc loop resistance of 100 ohms/km?

 a. 0.838 mm

 b. 0.465 mm

 c. 1.626 mm

 d. 2.159 mm

75. What kind of cell is appropriate for load management, fast moving mobiles and low-usage areas?

 a. Pico cells

 b. Micro cells

 c. Nano cells

 d. Umbrella cells

76. In cellular networks, standard base station antennas are placed by ______.  a. adaptive array

 b. flat plate antenna

 c. dipole array

 d. focused antenna

77. What is the basis of the first generation wireless local loop?

 a. Digital cellular technology

 b. Analogue cellular technology

 c. PSTN

 d. AMPS technology

78. When the calling party hears a “busy” tone on his telephone, the call is considered

 a. lost

 b. disconnected

 c. completed

 d. incomplete

79. Short-circuited stubs are preferred to open circuited stubs because the latter are

 a. more difficult to make and connect

 b. made of a transmission line with a different characteristic impedance

 c. liable to radiate

 d. incapable of giving a full range of reactances

80. What is the ratio of the reflected voltage to the incident voltage?

 a. VSWR

 b. ISWR

 c. SWR

 d. Coefficient of reflection 81. One method of determining antenna impedance.

 a. Sub matching

 b. Trial and error

 c. Smith chart

 d. Quarter-wave matching

82. ______is a single conductor running from the transmitter to the antenna.

 a. Single-wire line

 b. Microstrip

 c. Twin-lead

 d. Coaxial line

83. Coaxial cable impedance is typically ______.

 a. 150 to 300 ohms

 b. 50 to 75 ohms

 c. 30 to 45 ohms

 d. 300 to 600 ohms

84. Waveguide becomes compulsory above what frequencies?

 a. Above 3 GHz

 b. Above 10 kHz

 c. At 300 MHz

 d. Above 10 GHz

85. Nominal voice channel bandwidth is ______.

 a. 20 to 30 kHz

 b. 0 to 3 kHz

 c. 4 kHz  d. 55 kHz above

86. Echo suppressors are used on all communications system when the round trip propagation time exceeds ______.

 a. 50 ms

 b. 30 ms

 c. 100 ms

 d. 1 ms

87. A radio transmission line of 300 ohms impedance is to be connected to an antenna having an input impedance of 150 ohms. What is the impedance of a quarter-wave matching line?

 a. 212 ohms

 b. 250 ohms

 c. 200 ohms

 d. 150 ohms

88. Quarter-wavelength line is used as ______.

 a. impedance transformer

 b. lecher line

 c. transmission line

 d. harmonic suppressor

89. The transmission lines which can convey electromagnetic waves only in higher modes is usually called

 a. coaxial cable

 b. waveguide

 c. power lines

 d. twisted wire of telephone line

90. Why is nitrogen gas sometimes used in waveguide?

 a. To increase the distributed capacitance  b. To keep the waveguide dry

 c. To reduce the skin effect at the walls of the guide

 d. To raise the guide’s wave impedance

91. The apparent speed of propagation along a waveguide based on the distance between wavefronts along the walls of the guide is called

 a. group velocity

 b. phase velocity

 c. normal velocity

 d. abnormal velocity

92. How do you couple in and out of a waveguide?

 a. Wrap a coil of wire around one end of the waveguide

 b. Insertion of an E-probe into the waveguide

 c. Insertion of an H-loop into the waveguide

 d. Both B and C

93. A rectangular waveguide is operating in the dominant TE10 mode. The associated flux lines are established

 a. transversely across the narrow dimension of the waveguide

 b. transversely across the wide dimension of the waveguide

 c. in the metal walls parallel to the direction of propagation

 d. in the metal walls perpendicular to the direction of propagation

94. For dominant mode of a rectangular waveguide, the distance between two instantaneous consecutive positions of maximum field intensity (in a direction parallel to the walls of the waveguide) is referred to as half of the

 a. free-space wavelength

 b. cutoff wavelength in the wide dimension

 c. guide wavelength

 d. group wavelength 95. The guide wavelength, in a rectangular waveguide is

 a. equal to the free-space wavelength at the cutoff frequency

 b. equal to the free-space wavelength for the same signal frequency

 c. less than the free-space wavelength at the cut-off frequency

 d. greater than the free-space wavelength at the same signal frequency

96. Using the TE10 mode, microwave power can only be transmitted in free rectangular guide provided

 a. the wider dimension is less than one-half of the wavelength in free space

 b. the narrow dimension is less than one-quarter of the wavelength in free space

 c. the wide dimension is greater than one-half of the guide wavelength

 d. the wide dimension is greater than one-half of the wavelength in free space

97. If the signal frequency applied to a rectangular guide is increased and the dominant mode is employed

 a. the free space wavelength is increased

 b. the phase velocity increased

 c. the guide wavelength is increased

 d. the group velocity, Vg, is increased

98. If a 6 GHz signal is applied to a rectangular waveguide and the reflection angle is 20o, what is the value of the guide wavelength?

 a. 6.10 cm

 b. 5.32 cm

 c. 4.78 cm

 d. 5.00 cm

99. The inner dimensions of a rectangular wavelength are 1.75 cm by 3.5 cm. The cutoff wavelength for the dominant mode is

 a. 1.75 cm

 b. 3.5 cm  c. 7.0 cm

 d. 0.4375 cm

100. A signal whose wavelength is 3.5 cm is being propagated along a guide whose inner dimensions are 2 cm by 4 cm. What is the value of the guide wavelength?

 a. 3.12 cm

 b. 3.89 cm

 c. 3.57 cm

 d. 6.30 cm

51. Lost calls of 5% 52. 3, 700 Hz 77. Analogue cellular technology 53. 1000 lines 78. completed 54. Purely reactive 79. liable to radiate 55. 12 80. Coefficient of reflection 56. 36 CCS 81. Quarter-wave matching 57. WATS 82. Single-wire line 58. 300-3400 Hz 83. 50 to 75 ohms 59. Manual switching 84. Above 3 GHz 60. On-hook 85. 4 kHz 61. Varistor 86. 50 ms 62. Electromagnetic 87. 212 ohms 63. 0 to 4 kHz 88. impedance transformer 64. Basic voice grade (VG) 89. waveguide 65. Dial-up network 90. To keep the waveguide dry 66. Assure customer the telephone 91. phase velocity is working 92. Both B and C 67. Tie trunk 93. transversely across narrow 68. Tarif dimension of the waveguide 69. 3 dB 94. guide wavelength 70. 300-3400 Hz 95. greater than the free-space 71. 1897 wavelength at the same signal frequency 72. 52 μsec 96. the wide dimension is greater than 73. G. 122 one-half of the wavelength in free space 74. 0.465 mm 97. the group velocity, Vg, is increased 75. Umbrella cells 98. 5.32 cm 76. adaptive array 99. 7.0 cm 100. 3.89 cm 101. The frequency range over which a rectangular waveguide is excited in the dominant mode is limited to

 a. the difference between the frequency for which the reflection angle is 90o and the frequency for which angle is zero

 b. the difference between the frequency for which the free-space wavelength is equal to the cutoff value and the frequency for which the free-space wavelength is equal to the guide wavelength

 c. the difference between the frequency at which the cutoff wavelength is twice the narrow dimension

 d. none of these

102. If a rectangular waveguide is to be excited in the dominant mode, the E-probe should be inserted

 a. at the sealed end

 b. at a distance of one quarter –wavelength from the sealed end

 c. at a distance of one-half wavelength from the sealed end

 d. at a distance of three-quarters of a wavelength from the sealed end

103. A quarter-wave line is connected to an RF generator and is shorted out at the far end. What is the input impedance to the line generator?

 a. A low value of resistance

 b. A high value of resistance

 c. A capacitive resistance which is equal in the value to the line’s surge impedance

 d. An inductive resistance which is equal to the value to the line’s surge impedance

104. If the SWR on a transmission line has a high value, the reason could be

 a. an impedance mismatch between the line and the load

 b. that the line is non-resonant

 c. a reflection coefficient of zero at the load  d. that the load is matched to the line

105. If a quarter-wave transmission line is shorted at one end

 a. there is minimum current at the shorted end

 b. the line behaves as a parallel-tuned circuit in relation to the generator

 c. the line behaves as a series-tuned circuit in relation to the generator

 d. there is a minimum voltage at the shorted end

106. A 50-ohm transmission line is feeding an antenna which represents a 50 ohm resistive load. To shorten the line, the length must be

 a. any convenient value

 b. an odd multiple of three quarters of a wavelength

 c. an odd multiple of half a wavelength

 d. an even multiple of a quarter of a wavelength

107. The outer conductor of the coaxial cable is usually grounded

 a. at the beginning and at the end of the cable

 b. only at the beginning of the cable and only at the end of the cable

 c. only at the end of the cable

 d. at the middle of the cable

108. A feature of an infinite transmission line is that

 a. its input impedance at the generator is equal to the line’s surge impedance

 b. its phase velocity is greater than the velocity of light

 c. no RF current will be drawn from the generator

 d. the impedance varies at different positions on the line

109. When the surge impedance of a line is matched to a load, the line will

 a. transfer maximum current to the load

 b. transfer maximum voltage to the load  c. transfer maximum power to the load

 d. have a VSWR equal to zero

110. A lossless line is terminated by a resistive load which is not equal to the surge impedance. If the value of the reflection coefficient is 0.5, the VSWR is

 a. 2

 b. 3

 c. 4

 d. 15

111. Ratio of the mismatch between the antenna and the transmitter power.

 a. Standing wave pattern

 b. Reflection coefficient

 c. SWR

 d. Index of refraction

112. Emission designation for a facsimile.

 a. H3E and A4E

 b. R3E and A4E

 c. F4E and J3E

 d. F3C and A3E

113. Commonly used telephone wire.

 a. AWG #19

 b. AWG #18

 c. AWG #30

 d. AWG #33

114. What is the distance traveled by a wave in the time of one cycle?

 a. Frequency  b. Hop

 c. Wavelength

 d. Crest

115. The velocity factor is inversely proportional with respect to the ______.

 a. square of the dielectric constant

 b. square root of the dielectric constant

 c. dielectric current

 d. square root of refractive index

116. ______is a hollow structure that has no center conductor but allows waves to propagate down its length.

 a. Waveguide

 b. Hybrid

 c. Pipe

 d. Directional coupler

117. To connect a coaxial line to a parallel wire line, ______is used.

 a. hybrid circuit

 b. balun

 c. directional coupler

 d. quarter-wave transformer matching circuit

118. What length for which the input power has been halved for a transmission line with an attenuation of 6 dB/km?

 a. 1.5 km

 b. 0.5 km

 c. 63 km

 d. 2 km 119. Ina waveguide, ______is a specific configuration of electric and magnetic fields that allows a wave to propagate.

 a. set-up

 b. coupler

 c. channel

 d. mode

120. A rectangular waveguide has dimensions of 3 cm x 5 cm. What is the dominant mode cut-off frequency?

 a. 2 GHz

 b. 3 GHz

 c. 2.5 GHz

 d. 3.5 GHZ

121. ______are transmission lines which can convey electromagnetic waves only in higher order modes?

 a. Coaxial cables

 b. Twisted pairs of telephone wire

 c. Power cables

 d. Waveguides

122. The amount of uncertainty in a system of symbols is also called

 a. bandwidth

 b. loss

 c. entropy

 d. quantum

123. The twists in twisted wire pairs

 a. reduced electromagnetic interference

 b. occur at a 30-degree angle  c. eliminate loading

 d. were removed due to cost

124. An example of a bounded medium is

 a. coaxial cable

 b. waveguide

 c. fiber-optic cable

 d. all of the above

125. Loading means the addition of

 a. resistor

 b. capacitor

 c. bullet

 d. inductance

126. What is the most commonly used transmission line for high frequency application?

 a. Two-wire balance line

 b. Single wire

 c. Three-wire line

 d. Coaxial

127. The characteristic impedance of a transmission line does not depend upon its

 a. length

 b. conductor diameter

 c. conductor spacing

 d. dielectric material

128. One of the following is not a common transmission line impedance.

 a. 50 ohms  b. 75 ohms

 c. 120 ohms

 d. 300 ohms

129. For maximum absorption of power at the antenna, the relationship between the characteristic impedance of the line Zoand the load impedance ZL should be

 a. Zo = ZL

 b. Zo > ZL

 c. Zo < ZL

 d. Zo = 0

130. The mismatch between antenna and transmission line impedance cannot be corrected for by

 a. using LC matcging network

 b. adjusting antenna length

 c. using a balun

 d. adjusting the length of transmission line

131. ______is a pattern of voltage and current variations along a transmission line not terminated in its characteristic impedance.

 a. An electric field

 b. Radio waves

 c. Standing waves

 d. A magnetic field

132. Which is the desirable SWR on a transmission line?

 a. 0

 b. 1

 c. 2

 d. Infinity 133. A 50ohm coax is connected to a 73-ohm antenna. What is the SWR?

 a. 0.685

 b. 1

 c. 1.46

 d. 2.92

134. What is the most desirable reflection coefficient?

 a. 0

 b. 0.5

 c. 1

 d. Infinity

135. What is the ratio expressing the percentage of incident voltage reflected on a transmission line?

 a. Velocity factor

 b. Standing-wave ratio

 c. Reflection coefficient

 d. Line efficiency

136. The minimum voltage along a transmission line is 260 V, while the maximum is 390 V, the SWR is

 a. 0.67

 b. 1.0

 c. 1.2

 d. 1.5

137. One meter is one wavelength at a frequency of

 a. 150 MHz

 b. 164 MHz

 c. 300 MHz  d. 328 MHz

138. At very high frequencies, transmission lines act as

 a. Tuned circuits

 b. Antennas

 c. Insulators

 d. Resistors

139. A shorted quarter-wave line at the operating frequency acts like a/an

 a. Capacitor

 b. Inductor

 c. Series resonant circuit

 d. Parallel resonant circuit

140. A shorted half-wave line at the operating frequency acts like a/an

 a. Capacitor

 b. Inductor

 c. Series resonant circuit

 d. Parallel resonant circuit

141. A medium least susceptible to noise?

 a. Shielded pair

 b. Twisted pair

 c. Fiber-optic

 d. Coaxial

142. A medium most widely used in LANs?

 a. Parallel-wire line

 b. Twisted pair  c. Fiber-optic cable

 d. Coaxial

143. The most commonly used transmission line in television system.

 a. Parallel-wire line

 b. Coaxial cable

 c. Waveguide

 d. Open-wire ceramic supports

144. The impedance of a TV transmission line depends on several factors. Which is not one of those factors?

 a. Diameter

 b. Length of the wire

 c. Dielectric material

 d. Separation between conductors

145. DC blocks are used in coaxial transmission line for the purpose of

 a. passing DC while blocking AC

 b. passing AC voltage but prevent DC

 c. preventing AC voltage from reaching the pre-amplifier

 d. preventing AC power supply voltage from being shorted by a balun or band splitter

146. ______is a type of interference caused by off-air TV channels 2 and 4, plus a satellite dish operating on channel 3.

 a. Adjacent channel interference

 b. Ghost

 c. Co-channel interference

 d. Crosstalk

147. Dithering (in TVRO communication) is a process of  a. Reducing the effect of noise on the TVRO video signal

 b. Centering the video fine tuning on TVRO channels

 c. Moving the feedhorn rotor to the precise angle

 d. Moving the actuator exactly onto the desired satellite beam

148. A network that has an input of 75dB and an output of 35dB. The loss of the network is

 a. -40db

 b. 40db

 c. 40dBm

 d. -4dBm

149. Important useful quantities describing waveforms.

 a. Time and frequency

 b. Voltage and current

 c. Frequency and voltage

 d. Power and frequency

150. Halving the power means

 a. 6-dB gain

 b. 3-dB loss

 c. 3-dB gain

 d. 6-dB loss

101. the difference between the 105. the line behaves as a parallel- frequency at which the cutoff tuned circuit in relation to the wavelength is twice the narrow generator dimension 106. any convenient value 102. at a distance of one quarter – 107. at the beginning and at the end wavelength from the sealed end of the cable 103. A high value of resistance 108. its input impedance at the 104. an impedance mismatch between generator is equal to the line’s surge the line and the load impedance 109. transfer maximum power to the 130. adjusting the length of load transmission line 110. 3 131. Standing waves 111. SWR 132. 1 112. F3C and A3E 133. 1.46 113. AWG #19 134. 0 114. Wavelength 135. Reflection coefficient 115. square root of the dielectric 136. 1.5 constant 137. 300 MHz 116. Waveguide 138. Antennas 117. balun 139. Parallel resonant circuit 118. 0.5 km 140. Series resonant circuit 119. mode 141. Coaxial 120. 3 GHz 142. Twisted pair 121. Waveguides 143. Coaxial cable 122. entropy 144. Length of the wire 123. reduced electromagnetic 145. preventing AC power supply interference voltage from being shorted by a balun 124. all of the above or band splitter 125. inductance 146. Adjacent channel interference 126. Coaxial 147. Reducing the effect of noise on 127. length the TVRO video signal 128. 120 ohms 148. 40db 129. Zo = ZL 149. Frequency and voltage 150. 3-dB loss

151. One Neper (Np) is how many decibels?

 a. 8.866

 b. 8.686

 c. 8.688

 d. 8.868 152. A signal is amplified 100 times in power. The dB gain is

 a. 20 dB

 b. 119 dB

 c. 15 dB

 d. 25 dB

153. Which of the following is used to measure SWR?

 a. Spectrum analyzer

 b. Reflectometer

 c. Oscilloscope

 d. Multimeter

154. 214-056 twin lead which is commonly used for TV lead-in has a characteristic impedance of

 a. 52 ohms

 b. 75 ohms

 c. 600 ohms

 d. 300 ohms

155. What is the characteristic impedance of a transmission line which is to act a s a quarterwave matching transformer between a 175 ohms transmission line and 600 ohms load?

 a. 300.04 ohms

 b. 324.04 ohms

 c. 310.04 ohms

 d. 320.04 ohms

156. What is the EIRP in dBW of a 50dB antenna connected to a transmitter with an output of 10kW through a transmission line with loss of 5dB?

 a. 85 dBW

 b. 955 dBW  c. 90 dBW

 d. 80 dBW

157. A coaxial cable is a good example of a/an

 a. Unbounded medium

 b. Transmission channel

 c. Non-metallic medium

 d. Bounded medium

158. If a quarterwave transformer is required to match a 180 ohm load to a transmission line with and impedance of 300 ohms, what should be the characteristic impedance of the matching ransformer? Assume that the matching transformer is to be connected directly to the load.

 a. 180 ohms

 b. 232 ohms

 c. 300 ohms

 d. 480 ohms

159. A transmitter of 100W RF power output, 100% modulated is operating on a frequency of 169MHz. The antenna transmission line consists of a 50 ohms coaxial cable 150ft long. The coaxial inner conductor outer diameter is 0.162in. determine the outside diameter of the outer conductor if the outer conductor has a thickness of 0.05 in(assume K=1).

 a. 1.0 in

 b. 0.9 in

 c. 0.7 in

 d. 0.5 in

160. In the preceding problem , calculate the line current.

 a. 1.7A

 b. 1.3A

 c. 1.5A

 d. 1.0A 161. Determine also the total attenuation of the line in the preceding problem.

 a. 2.0dB

 b. 1.5 dB

 c. 2.5 dB

 d. 1.0 dB

162. What is the maximum subscriber loop length, in ft, of a telephone system if the signaling resistance is 1800ohms using a telephone cable pair of gauge #26 with loop resistance of 83.5 ohms per 100ft. Assume the telephone set resistance is equal to 200 ohms.

 a. 15,161.7 feet

 b. 19,161 feet

 c. 15,300 feet

 d. 20,000 feet

163. If the same subscriber loop above limits the voice attenuation to a maximum of 6dB, what is the maximum allowable subscriber loop length, in feet, using the same gauge #26 telephone wire? Assume a 2.7dB loss per mile.

 a. 20,000 ft

 b. 13,900 ft

 c. 15,280 ft

 d. 11,733 ft

164. The input is 0.1W and the network gain is 13dB, the output is

 a. 2.0 W

 b. 2.5 W

 c. 1.5 W

 d. 1.8 W

165. Known as one-tenth of a neper.

 a. dB

 b. dBm  c. dBp

 d. dNp

166. the input impedance of a quarterwave short-circuited transmission line at its resonant frequency is

 a. 0 ohms

 b. Infinite or an open circuit

 c. Ohm

 d. 70 ohms

167. The ratio of the largest rms value to the smallest rms value of the voltage in the line is called

 a. SWR

 b. ISWR

 c. VSWR

 d. Coefficient of reflection

168. An open-wire, two-wire transmission line is to be connected to a dipole antenna through a quarter- wave matching stub. At a frequency of 10 MHz, compute the length of the dipole

 a. 20 meters

 b. 7.5 meters

 c. 15 meters

 d. 25 meters

169. From the preceding problem, compute also the length of the quarterwave stub.

 a. 15 meters

 b. 7.5 meters

 c. 20 meters

 d. 25 meters

170. To find the characteristic impedance of a coaxial cable, measurements are made with (a) the far end open circuited and (b) far end short circuited, the corresponding readings being a) Ro=3ohms and Xc=55 ohms, capacitive b) RS = 10 ohms and XL = 90 ohms, inductive. What is the characteristic impedance Zo of the line?  a. 75.7 - j2.0 ohms

 b. 70.7 + j1.19 ohms

 c. 87.5 – j5 ohms

 d. 70.7 – j1.97 ohms

171. A TV antenna receives a signal measured at 200mV and is immediately amplified by a preamplifier with a 15dB gain. This amplified signal then passes through a coaxial cable with 3dB loss, what is the resulting input to the TV set, in dBmV?

 a. 1.98

 b. 13.98

 c. -1.98

 d. -13.98

172. The characteristic impedance of a transmission line does not depend upon its______.

 a. Conductor spacing

 b. Conductor diameter

 c. Length

 d. Conductor radius

173. What does a power difference of -3dB mean?

 a. A loss of one third of the power

 b. A loss of one half of the power

 c. A loss of three watts of power

 d. No significant change

174. Which of the following is an advantage of the balance transmission line?

 a. Easy installation

 b. Outer shield eliminates radiation losses

 c. Low attenuation  d. None of these

175. Waveguides are used mainly for microwave transmission because

 a. They are bulky at lower frequencies

 b. Losses are heavy at lower frequencies

 c. They depend on straight line propagation

 d. No generators are powerful enough to excite them

176. The input is 1W and the network loss is 27dB, the output is

 a. 1 mW

 b. 3 mW

 c. 2 mW

 d. 4 mW

177. A combiner has two inputs +30dBm and +30dBm, what is the resultant output?

 a. +36 dBm

 b. +30 dBm

 c. +60 dBm

 d. +33 dBm

178. The ratio of the smallest to the largest rms current value is called

 a. SWR

 b. VSWR

 c. ISWR

 d. Coefficient of reflection

179. If the ratio of the maximum current to minimum current in a transmission line is 2:1 then the ratio of the maximum voltage to minimum voltage is

 a. 4:1

 b. 1:2  c. 1:4

 d. 2:1

180. Two wires of 600 ohms characteristic impedance is to be constructed out of a number 12 wire (81 mils). Find the attenuation of the line at 0.6GHz per 100feet length

 a. 0.05 dB

 b. 0.55 dB

 c. 0.44 dB

 d. 0.35 dB

181. In the preceding problem, determine the spacing between wires from center to center.

 a. 6 in

 b. 4 in

 c. 5 in

 d. 3 in

182. A lossless transmission line has a shunt capacitance of 100nF/m and a series inductance of 4mH/m. What is the characteristic impedance?

 a. 500 ohms

 b. 400ohms

 c. 300 ohms

 d. 200 ohms

183. A ten times power change in transmission system is equivalent to

 a. 10 dBm

 b. 1 dB

 c. 20 dB

 d. 100 dB

184. A type of transmission line employed where balanced properties are required.  a. Balun

 b. Parallel-wire line

 c. Coaxial line

 d. Quarterwave line

185. What is the characteristic impedance of a transmission line which has a capacitance of 40nF/ft and an inductance of 0.5mH/ft

 a. 111.8 ohms

 b. 110.8 ohms

 c. 112.8 ohms

 d. 109.8 ohms

186. The input power to a loss-free cable is 5W. If the reflected power is 7dB down on the incident power, the output power to the load is

 a. 4 W

 b. 5 W

 c. 6 W

 d. 7 W

187. To be properly matched the ratio of a maximum voltage along a transmission line should be equal to

 a. 1

 b. 10

 c. 50

 d. 2

188. A coaxial line with an outer diameter of 6mm has a 50 ohms characteristic impedance. If the dielectric constant of the insulation is 1.60., calculate the inner diameter.

 a. 2.09 cm

 b. 2.09 in

 c. 2.09 mm  d. 2.09 mm

189. If an amplifier has equal input and out impedance, what voltage ratio does the gain of 50dB represent?

 a. 316.2

 b. 325.2

 c. 320.1

 d. 315.0

190. What is the inductance per foot of a cable that has a capacitance of 50 pF/ft and a characteristic impedance of 60 ohms?

 a. 0.167uH/ft

 b. 0.178 uH/ft

 c. 0.19 uH/ft

 d. 0.18 uH/ft

191. The ratio between the energy absorbed by a surface to the total energy received by the surface.

 a. Reflection coefficient

 b. Absorption coefficient

 c. Linear coefficient

 d. Thermal coefficient

192. When the diameter of the conductors of a wire transmission line is held constant, the effect of decreasing the distance between the conductors is

 a. Increase the surge impedance

 b. Increase the radiation resistance

 c. Decrease the SWR

 d. Decrease the impedance

193. The higher the gauge number if a conductor

 a. The bigger the diameter  b. The higher the resistance or the smaller the diameter

 c. The higher the resistance

 d. None of the above

194. A short length transmission line used to reduce/eliminate standing waves in the main transmission line.

 a. Stub

 b. Balun

 c. λ/4 transformer

 d. slot

195. ratio of reflected power to incident power?

 a. Incidence

 b. Reflectance

 c. Reflection index

 d. None of these

196. A quarter wave transformer is used to match a 600 ohms lad antenna to a ling of 52 ohms impedance, the characteristic impedance of the matching transformer is

 a. 200 ohms

 b. 150 ohms

 c. 176 ohms

 d. 300 ohms

197. What is the capacitance of 55 miles #44 copper wire spaced 18 inches? From wire tables, #44 wire has a radius to 0.10215 in.

 a. 0.476 uF

 b. 0.476 nF

 c. 0.476 pF

 d. 0.476 fF 198. A two-transmission line consists of No. 12 wire AWG (81mils). The distance between wire centers is 10 inches. What is the characteristic impedance of the line?

 a. 650 ohms

 b. 300 ohms

 c. 600 ohms

 d. 660 ohms

199. In the preceding problem, what is the attenuation in dB per 100ft of the line for a frequency of 4 MHz?

 a. 0.05

 b. 0.03

 c. 0.04

 d. 0.06

200. What is the SWR when a transmission line is terminated in a short circuit?

 a. Zero

 b. One

 c. Infinite

 d. indeterminate

151. 8.686 166. Infinite or an open circuit 152. 20 dB 167. VSWR 153. Reflectometer 168. 15 meters 154. 300 ohms 169. 7.5 meters 155. 324.04 ohms 170. 70.7 – j1.97 ohms 156. 85 dBW 171. -1.98 157. Bounded medium 172. Length 158. 232 ohms 173. A loss of one half of the power 159. 0.5 in 174. Low attenuation 160. 1.7A 175. No generators are powerful 161. 1.5 dB enough to excite them 162. 19,161 feet 176. 2 mW 163. 11,733 ft 177. +33 dBm 164. 2.0 W 178. ISWR 165. dNp 179. 2:1 180. 0.44 dB 191. Absorption coefficient 181. 6 in 192. Decrease the impedance 182. 200 ohms 193. The higher the resistance or the 183. 1 dB smaller the diameter 184. Parallel-wire line 194. λ/4 transformer 185. 111.8 ohms 195. Reflectance 186. 4 W 196. 176 ohms 187. 1 197. 0.476 uF 188. 2.09 mm 198. 660 ohms 189. 316.2 199. 0.03 190. 0.18 uH/ft 200. Infinite

201. If the 10% of the microwave power is reflected at the mismatch, find the return loss.

 a. 0.1 dB

 b. 10 dBm

 c. -10 dB

 d. -10 dBm

202. If the return loss is 20 dB, find the present reflected power.

 a. 1%

 b. 10%

 c. 5%

 d. 20%

203. Convert “ten times bigger” to the equivalent numerical dB

 a. 20 dB

 b. 15 dB

 c. 5 dB

 d. 10 dB

204. Convert “one-half as large” to equivalent numerical dB  a. 3 dB

 b. -3 dB

 c. 2 dB

 d. -2 dB

205. Special semiconductor diode use for electronically adjustable attenuation

 a. Ideal diode

 b. PIN diode

 c. Zener diode

 d. Tunel diode

206. A 50 ohm line is probed and found to have a SWR of 2.6, what are the two possible quarter wave transformers sizes that may be used to match the load to the line of the transformer are properly positioned.

 a. 22 ohm, 82 ohm

 b. 31 ohm, 80.5 ohm

 c. 26.2 ohm, 12.71 ohm

 d. 12.32 ohm, 26.7 ohm

207. A balanced load of 900 ohm pure resistance is fed through a balanced 600 ohm transmission line which is 90 electrical degree long. The balanced 600 ohm transmission line is in turn fed from a 50 ohm coaxial line by means of a half-wave balancing section. What is the standing wave ratio on the 600 ohm line?

 a. 1.0

 b. 2.5

 c. 1.5

 d. 2.0

208. Given cascaded circuit; first stage is a filter circuit with insertion loss of 3 dB, followed by an amplifier with a gain of 10 dB and followed by cable having an insertion loss of 1 dB. If the input power of the filter circuit is 1 mW, find the total insertion loss.

 a. 6 dBm  b. 5 dBm

 c. 7 dBm

 d. 2 dBm

209. For a short circuited line or open circuited line, the standing wave ratio value is always _____.

 a. Unity

 b. Infinity

 c. Zero

 d. Cannot be determined

210. If the voltage reading at a particular section of a transmission line is maximum, the current reading should be:

 a. Maximum

 b. Minimum

 c. Average

 d. Zero

211. If five signals entered to an X-device at 3 dBm each, find the output power in dBm.

 a. 12 dBm

 b. 11 dBm

 c. 10 dBm

 d. 8 dBm

212. Given incident power of 0.4 mW and insertion loss of 3 dB, find the transmitted power.

 a. 0.2 mW

 b. 0.3 mW

 c. 0.4 mW

 d. 0.5 mW

213. The reflected voltage and reflected current along the transmission line are always:  a. 180o out of phase

 b. In phase

 c. Same value

 d. 90o in phase

214. If the direction of the reflection coefficient is 90o, the nature of the lien is,

 a. Resistive

 b. Purely inductive

 c. Purely capacitive

 d. None of these

215. What are the three types of microwave transmission line?

 a. Coaxial cable, open wire line, waveguide

 b. Coaxial cable, stripline, waveguide

 c. Open-wire line, waveguide, coaxial line

 d. None of these

216. If the incident power is -27 dBm and insertion loss of 20 dB, find for the transmitted power.

 a. 12 dBm

 b. 7 dBm

 c. 2 dBm

 d. 0 dBm

217. Energy applied to a transmission line may become dissipated before reaching the load.

 a. Radiation

 b. Conductor heating

 c. Dielectric heating

 d. All of the above 218. The velocity of light is very nearly 3 x 108 m/s in a vacuum and ___ in all other media.

 a. Higher

 b. Slower

 c. Same

 d. All of these

219. At a point exactly a quarter-wavelength from the load, the current is ______.

 a. 180 degrees in of phase

 b. 180 degrees out of phase

 c. Permanently zero

 d. None of these

220. Is a piece of transmission line which is normally short-circuited at the far end.

 a. Terminator

 b. Stub

 c. Quarter wave transformer

 d. None of these

221. For high frequencies, the best dielectric may be______.

 a. Polyethylene

 b. Polyethylene foam

 c. Teflon

 d. None of these

222. Characteristic impedance are sometimes called ______.

 a. Ohmic resistance

 b. Surge impedance

 c. Wave impedance  d. None of these

223. A transmission line is connected to a mismatched load. Calculate the VSWR in dB if the reflection coefficient is 0.25

 a. 2.6 dB

 b. 1.67 dB

 c. 4.3 dB

 d. 3.6 dB

224. Is a power tool for the RF design

 a. Calculator

 b. Graphical solution

 c. Smith chart

 d. None of these

225. When will the system encounter a tremendous increase of interference.

 a. When return loss is 0 dB

 b. When the incident power is higher than the reflected

 c. When the transmission line used is coaxial cable

 d. None of these

226. In a two-stage amplifier, amplifier 1 has a noise figure of 3 dB and a gain of 20 dB. The second amplifier has a noise figure of 6 dB. Find the total noise figure.

 a. 3.1 dB

 b. 4.2 dB

 c. 2.6 dB

 d. 2.27 dB

227. If the return loss is 13 dB, find the equivalent SWR.

 a. 1.6  b. 3.2

 c. 1.56

 d. 2.6

228. Which of the following will you choose in order to minimize mismatch?

 a. SWR = 1.4

 b. T1 = 0.81

 c. Return loss = 20 dB

 d. None of these

229. If the equipment has input power of 33 dBm, what is the gain of the resulting output power is 10 dBm.

 a. -26 dBm

 b. -23 dBm

 c. -33 dBm

 d. 33 dBm

230. A stripline transmission line is built on a 4 mm thick printed wiring board that has a relative dielectric constant of 5.5. Calculate the characteristics impedance of the width of the strip is 2 mm.

 a. 256 ohms

 b. 321 ohms

 c. 126 ohms

 d. 425.35 ohms

231. A 50 ohms transmission line is connected to a 30 ohm resistive load. Calculate reflection coefficient.

 a. 0.35

 b. 0.25

 c. 0.10

 d. 0.15 232. The term ______implies a sine wave of constant amplitude, phase and frequency.

 a. Steady state

 b. State of constant

 c. State of calamity

 d. Constant sine wave

233. Is defined as the ratio of the reflected signal to the incident signal.

 a. VSWR

 b. SWR

 c. Reflection coefficient

 d. None of these

234. It is a measure of one way loss of power in a transmission line due to reflection from the load.

 a. Return loss

 b. Transmission loss

 c. Propagation loss

 d. None of these

235. If the velocity factor is equal to 0.66, the speed of light will be_____.

 a. Increase

 b. Decrease

 c. Same

 d. None of these

236. In 1939, ______published a graphical device for solving transmission line design.

 a. Phillip A. Smith

 b. Phillip R. Smith

 c. Phillip H. Smith  d. Phillip S. Smith

237. In order to make the smith chart universal, the impedances along the pure resistance line are ______.

 a. Normal

 b. Normalized

 c. Open circuit

 d. Short circuit

238. Calculate the gain off an amplifier with an input power 10 kW and an output power of 200 kW.

 a. 15 dB

 b. 13 dB

 c. 20 dB

 d. 10 dB

239. A perfect termination for a transmission line.

 a. Receiving end

 b. Load

 c. Antenna

 d. Terminal end

240. It can be measured, and includes losses due to reflection and absorption inside the component

 a. Fading

 b. Attenuation

 c. Insertion loss

 d. Return loss

241. A component that samples the microwave signal traveling in one direction down a transmission line

 a. Isolator

 b. Directional coupler  c. Combiner

 d. attenuator

242. A transmission line having air dielectric is operated at a frequency of 110 MHz. What is the phase shift constant of the line is degrees per inch?

 a. 2.56

 b. 3.35

 c. 4.6

 d. 1.25

243. Consider the three networks in series, the first is an attenuator with a 12 dB loss, the second network is an amplifier with 35 dB gain, and the third has an insertion loss of 10 dB. The input of the first network is 4 mW; what is the output of the third network in watts?

 a. 0.798 W

 b. 0.00798 W

 c. 0.0798 W

 d. 798 W

244. Is a power level related to 1 mW.

 a. dB

 b. dBm

 c. dBM

 d. dBW

245. A transmission unit used in a number of Northern European countries as an alternative to the decibel is ______.

 a. Attenuation

 b. Loss

 c. Neper

 d. dB loss

246. Adding two +30 dBm will produce how much dBm at the output.  a. 60 dBm

 b. 15 dBm

 c. 23 dBm

 d. 33 dBm

247. Determines how the voltage or current decreases with distance

 a. Phase-shift coefficient

 b. Attenuation coefficient

 c. Propagation coefficient

 d. Numerical coefficient

248. Determines the phase angle of the voltage or current variation with distance

 a. Phase-shift coefficient

 b. Attenuation coefficient

 c. Propagation coefficient

 d. Numerical coefficient

249. Determines variation of voltage or current with distance along transmission line

 a. Phase-shift coefficient

 b. Attenuation coefficient

 c. Propagation coefficient

 d. Numerical coefficient

250. The R, L, G, and C in the transmission line are called______.

 a. Passive elements

 b. Active elements

 c. Line primary constant

 d. Reactances 201. -10 dB 226. 3.1 dB 202. 1% 227. 1.56 203. 10 dB 228. T1 = 0.81 204. -3 dB 229. -23 dBm 205. PIN diode 230. 321 ohms 206. 31 ohm, 80.5 ohm 231. 0.25 207. 1.5 232. Steady state 208. 6 dBm 233. Reflection coefficient 209. Infinity 234. Transmission loss 210. Minimum 235. Decrease 211. 10 dBm 236. Phillip H. Smith 212. 0.2 mW 237. Normalized 213. 180o out of phase 238. 13 dB 214. Purely inductive 239. Load 215. Coaxial cable, stripline, 240. Insertion loss waveguide 241. Directional coupler 216. 7 dBm 242. 3.35 217. All of the above 243. 0.0798 W 218. Slower 244. dBm 219. Permanently zero 245. Neper 220. Stub 246. d. 33 dBm 221. Teflon 247. Attenuation coefficient 222. Surge impedance 248. Phase-shift coefficient 223. 4.3 dB 249. Propagation coefficient 224. Smith chart 250. Line primary constant 225. When return loss is 0 dB

251. What is the characteristic impedance of a single wire with diameter d = 0.25 mm placed at the center between parallel planes separated by 1 mm apart? The wire is held by a material with a velocity factor of 0.75?

 a. 75 ohms  b. 120 ohms

 c. 100 ohms

 d. 300 ohms

252. There is an improper impedance match between a 30 W transmitter and the antenna and 5 W is reflected. How much power is actually transmitted?

 a. 35 W

 b. 25 W

 c. 30 W

 d. 20 W

253. What is the actual length in feet of a one quarter-wavelength of a coax with a velocity factor of 0.69 at 40 MHz?

 a. 6.15

 b. 4.244

 c. 5.904

 d. 16.974

254. A quarter-wave line is connected to an RF generator and is shorted out at the far end. What is the input impedance to the line at the generator?

 a. A low value of resistance

 b. A high value of resistance

 c. A capacitive reactance which is equal in value to the line’s surge impedance

 d. A value of resistance equal to the characteristic impedance of the line

255. A coaxial cable has a capacitance of 90pF/m and a characteristic impedance of 75 ohms. Find the inductance of a 2m length.

 a. 1.013 uH

 b. 450 nH

 c. 506.25 nH

 d. 225 nH 256. If the SWR on a transmission line has high value, the reason could be

 a. An impedance mismatch between the line and the load

 b. That the line is nonresonant

 c. A reflection coefficient of zero at the load

 d. A high degree of attenuation between the load and the position where the SWR is measured

257. Calculate the velocity factor of a coaxial cable used as a transmission line with the characteristic impedance of 50 ohms; capacitance is 40 pF/m and an inductance equal to 50 microH/m.

 a. 0.7450

 b. 0.7504

 c. 0.0745

 d. 0.0475

258. If a quarter-wave transmission line is shorted at one end

 a. There is minimum current at the shorted end

 b. The line behaves as a parallel-tuned circuit in relation to the generator

 c. The line behaves as a series tuned circuit in relation to the generator

 d. There is a maximum voltage at the shorted end

259. What is the velocity factor for a cable with a Teflon dielectric (relative permittivity = 2.1)?

 a. 0.69

 b. 0.476

 c. 2.1

 d. 1.449

260. A 50-ohm transmission line is feeding an antenna which represents a 50-ohm resistive load. To shorten the line, the length must be

 a. Any convenient value

 b. An odd-multiple of three-quarters of a wavelength  c. An even multiple of a quarter of a wavelength

 d. An odd multiple of an eight of a wavelength

261. A feature of an infinite transmission line is that

 a. Its input impedance at the generator is equal to the line’s surge impedance

 b. Its phase velocity is greater than the velocity of light

 c. The impedance varies at different positions on the line

 d. The input impedance is equivalent to a short circuit

262. The outer conductor of the coaxial cable is usually grounded

 a. At the beginning and at the end of the cable

 b. Only at the beginning of the cable

 c. Only at the end of the cable

 d. The outer conductor must never be grounded

263. What is the impedance of a balance 4-wire with a diameter of 0.25 cm and spaced 2.5 cm apart using an insulator with a dielectric constant of 2.56?

 a. 100 ohms

 b. 160.5 ohms

 c. 88.93 ohms

 d. 25.8 ohms

264. An attenuator has a loss of 26 dB. If a power of 3 W is applied to the attenuator, find the output power.

 a. 1.65 watts

 b. 7.54 milliwatts

 c. 1194 watts

 d. 5.459 watts

265. When surge impedance of a line is matched to a load, the line will  a. Transfer maximum current to the load

 b. Transfer maximum voltage to the load

 c. Transfer maximum power to the load

 d. Have a VSWR equal to zero

266. A lossless line is terminated by a resistive load which is not equal to the surge impedance. If the value of the reflection coefficient is 0.5, the VSWR is

 a. 2

 b. 3

 c. 1.5

 d. 5

267. The best insulation at UHF is

 a. Black rubber

 b. Bakelite

 c. Paper

 d. Mica

268. Neglecting line losses, the RMS voltage along an RF transmission line having no standing waves

 a. Is equal to the impedance

 b. Is one-half of the surge impedance

 c. Is the product of the surge impedance and the lien current

 d. Varies sinusoidally along the line

269. What length of standard RG-8/U coaxial cable would be required to obtain a 30 degree-phase shift at 250 MHz?

 a. 0.792 m

 b. 0.99 m

 c. 0.066 m  d. 0.124 m

270. Nitrogen is placed in transmission lines to

 a. Improve the skin-effect of microwaves

 b. Reduce arcing in the line

 c. Reduce the standing wave ratio of the line

 d. Prevent moisture from entering the line

271. Referred to the fundamental frequency, a shorted stub line attached to the transmission line to absorb even harmonics could have a wavelength of

 a. 1.41 wavelength

 b. ½ wavelength

 c. ¼ wavelength

 d. 1/6 wavelength

272. Nitrogen gas in concentric RF transmission lines is used to

 a. Keep moisture out

 b. Prevent oxidation

 c. Act as insulator

 d. Both A and B

273. If a transmission line has a power loss of 6 dB per 100 feet, what is the power at the feed point to the antenna at the end of a 200 foot-transmission line fed by a 100 watt transmitter?

 a. 70 watts

 b. 50 watts

 c. 25 watts

 d. 6 watts

274. Two adjacent minima on a slotted line are 20 cm apart. Find the wavelength assuming a velocity factor of 95 %.

 a. 38 m  b. 43.7 m

 c. 46 cm

 d. 40 cm

275. What would be the approximate series impedance of a quarter-wave matching line used to match a 600 ohm-feed to 70 ohm-antenna?

 a. 205 ohms

 b. 210 ohms

 c. 25.88 ohms

 d. 102.5 ohms

276. Which of the following represents the best SWR?

 a. 1:1

 b. 1:2

 c. 1:15

 d. 2:1

277. An optical domain reflectometer display shows a discontinuity 1.4 microsecond s from the start. If the line has a velocity factor of 0.92, how far is the fault from the reflecto meter?

 a. 168 m

 b. 193.2 m

 c. 210 m

 d. 386 m

278. A high SWR creates losses in a transmission line. A high standing wave ratio might be caused by

 a. Improper turns ratio between primary and secondary in the plate tank transformer

 b. Screen grid current flow

 c. An antenna electrically too long for its frequency

 d. An impedance mismatch 279. A properly connected transmission line

 a. Is grounded at the transmitter end

 b. Is cut to a harmonic of the carrier frequency

 c. Is cut to an even harmonic of the carrier frequency

 d. Has a standing wave ratio as near as 1:1 as possible

280. If a ¾ wavelength transmission is shorted at one end, the impedance at the open will be

 a. Zero

 b. Infinite

 c. Decreased

 d. Increased

281. The characteristic impedance of a transmission line does not depend upon its

 a. Length

 b. Conductor diameter

 c. Conductor spacing

 d. None of the above

282. Which of the following is not a common transmission line impedance?

 a. 50 ohms

 b. 75 ohms

 c. 120 ohms

 d. 300 ohms

283. A ratio expressing the percentage of incident voltage reflected on a transmission line is known as the

 a. Velocity factor

 b. Standing wave ratio

 c. Reflection coefficient  d. Line efficiency

284. A series tuned circuit operating at a frequency of 1 GHz is to be constructed from a shorted section of Teflon-dielectric coaxial cable. What length should be used? ( relative dielectric = 2.1)

 a. 0.325m

 b. 0.10 m

 c. 0.217 m

 d. 0.143 m

285. A 75 ohm line is terminated in a 30 ohm resistance. Find the SWR.

 a. 0.6

 b. 0.429

 c. 2.5

 d. 0.4

286. A generator sends 50 mW down a 50 ohm line. The generator is matched to the line but the load is not. If the coefficient of reflection is 0.6, how much power is reflected?

 a. 18 mW

 b. 20 mW

 c. 30 mW

 d. 32 mW

287. At very high frequencies, transmission lines are used as

 a. Tuned circuits

 b. Antennas

 c. Insulators

 d. Resistors

288. Transmission line shielding is grounded

 a. At the input only  b. At both the input and output

 c. At the output only

 d. If the antenna is a Marconi design

289. A shorted quarter-wave line at the operating frequency acts like a(an)

 a. Series resonant circuit

 b. Parallel resonant circuit

 c. Capacitor

 d. Inductor

290. A transmitter is required to deliver 100 W to an antenna through 5 m of coaxial cable with a loss of 3 dB / 100 m. What must be the output power of the transmitter, assuming the line is matched?

 a. 136 W

 b. 153 W

 c. 151 W

 d. 116.815 W

291. A generator sends 50 mW down a 50 ohm line. The generator is matched to the line but the load is not. If the coefficient of reflection is 0.25, how much power is dissipated in the load?

 a. 46.9 mW

 b. 37.5 mW

 c. 3.125 mW

 d. 12.5 mW

292. Determine the Q of an antenna if it has a bandwidth of 0.06 MHz and is cut to a frequency of 30 MHz.

 a. 50

 b. 100

 c. 150

 d. 250 293. The main disadvantage of the two-hole directional coupler is

 a. Low directional coupling

 b. Poor directivity

 c. High SWR

 d. Narrow bandwidth

294. A shorted half-wave line at the operating frequency acts like a(an)

 a. Capacitor

 b. Inductor

 c. Series resonant circuit

 d. Parallel resonant circuit

295. A load impedance of 100+j25 ohms is normalized on a 100 ohm-line. The normalized value is

 a. 2 + j0.5 ohms

 b. 0.25 - j1 ohms

 c. 0.94 - j24 ohms

 d. 1 + 0.25 ohms

296. A pattern of voltage and current variations along a transmission line not terminated in its characteristic impedance is called

 a. Electric field

 b. Radio waves

 c. Standing waves

 d. Magnetic field

297. A 75-j50 ohms is connected to a coaxial transmission line of ZO = 75 ohms, at 10 GHz. The best method of matching consists in connecting

 a. A short-circuited stub at the load

 b. An inductance at the load  c. A capacitance at some specific distance from the load

 d. A short-circuited stub at some specific distance from the load

298. Calculate the impedance seen looking into a 75 ohm line 1 m long terminated in a load impedance of 100 ohms, if the line has a velocity factor 0f 0.8 and operates at a frequency of 30 MHz.

 a. 72 - j21 ohms

 b. 75 - j25 ohms

 c. 40 - j30 ohms

 d. 50 - j25 ohms

299. The velocity factor of a transmission line

 a. Depends on the dielectric of the material used

 b. Increases the velocity along the transmission line

 c. Is governed by the skin effect

 d. Is higher for a solid dielectric than for air

300. A transmitter supplies 50 W to a load through a line with an SWR of 4:1. Find the power absorbed by the load.

 a. 32 W

 b. 5.6 W

 c. 44.4 W

 d. 18 W

251. 75 ohms 259. 0.69 252. 30 W 260. Any convenient value 253. 4.244 261. Its input impedance at the 254. A high value of resistance generator is equal to the line’s surge 255. 1.013 uH impedance 256. An impedance mismatch between 262. At the beginning and at the end the line and the load of the cable 257. 0.0745 263. 100 ohms 258. The line behaves as a parallel- 264. 7.54 milliwatts tuned circuit in relation to the 265. Transfer maximum power to the generator load 266. 3 283. Reflection coefficient 267. Mica 284. 0.10 m 268. Is the product of the surge 285. 2.5 impedance and the lien current 286. 18 mW 269. 0.066 m 287. Tuned circuits 270. Prevent moisture from entering 288. At both the input and output the line 289. Parallel resonant circuit 271. ¼ wavelength 290. 136 W 272. Both A and B 291. 46.9 mW 273. 6 watts 292. 50 274. 43.7 m 293. Narrow bandwidth 275. 205 ohms 294. Series resonant circuit 276. 1:1 295. 1 + 0.25 ohms 277. 193.2 m 296. Standing waves 278. An impedance mismatch 297. A short-circuited stub at some 279. Has a standing wave ratio as specific distance from the load near as 1:1 as possible 298. 72 - j21 ohms 280. Infinite 299. Depends on the dielectric of the 281. Length material used 282. 120 ohms 300. 32 W

301. Category of media with some form of conductor that provides a conduit in which electromagnetic signals are contained.

 A. Guided

 B. Balanced

 C. Unguided

 D. Unbalanced

302. The conductive connections between elements which carry signals.

 A. Transmission Lines

 B. Antenna

 C. Frequency allocations

 D. Load

303. Calculate the characteristic impedance for a line that exhibits an inductance of 4 nH/m and 1.5 pF/m  A. 36.6 ohms

 B. 51.6 ohms

 C. 22 ohms

 D. 24.5 ohms

304. Category of media which are wireless

 A. Guided

 B. Balanced

 C. Unguided

 D. Unbalanced

305. It is a medium or any physical facility used to propagate electromagnetic signals between two locations in a communications system.

 A. Transmission medium

 B. Channel allocation

 C. Frequency allocation

 D. Any of these

306. It is a metallic conductor system used to transfer electrical energy from one point to another using electrical current flow.

 A. Transmitter

 B. Multiplexers

 C. Receiver

 D. Transmission line

307. A kind of wave where the displacement is in the direction of propagation.

 A. Transverse

 B. Longitudinal

 C. Reverse  D. Perpendicular

308. Calculate the capacitance per meter of a 50-ohm load cable that has an inductance of 55 nH/m.

 A. 13 pF

 B. 18 pF

 C. 20 pF

 D. 22 pF

309. The desirable SWR on a transmission line is

 A. 0

 B. 1

 C. 2

 D. Infinity

310. A kind of wave where the direction is displacement is perpendicular to the direction of propagation.

 A. Transverse

 B. Longitudinal

 C. Reverse

 D. Perpendicular

311. A short-circuited half-wavelength line acts like a

 A. Parallel resonant circuit

 B. Series Resonant Circuit

 C. Oscillator

 D. LC circuit

312. Electromagnetic waves that travel along a transmission line from the source to the load.

 A. Reverse waves

 B. Transverse waves  C. Incident waves

 D. Longitudinal waves

313. Electromagnetic waves that travel from the load back toward the source.

 A. Incident waves

 B. Transverse waves

 C. Forward waves

 D. Reflected waves

314. Sound travels approximately

 A. 2200 feet per second

 B. 1100 feet per second

 C. 550 feet per second

 D. 600 feet per second

315. Determine the surge impedance for a parallel wire, air dielectric with a ratio of the spacing between conductors and the diameter of 3.

 A. 250 ohms

 B. 210 ohms

 C. 180 ohms

 D. 215 ohms

316. The rate at which the periodic wave repeats

 A. Wavelength

 B. Amplitude

 C. Period

 D. Frequency

317. The distance of one cycle occurring in space

 A. Wavelength  B. Amplitudes

 C. Period

 D. Frequency

318. Classification of transmission line where both conductors carry current; one conductor carries the signal, the other conductor is the return path

 A. Differential transmission lines

 B. Unbalanced lines

 C. Coaxial cables

 D. Balun

319. A shorted half-wave line at the operating frequency acts like

 A. Capacitor

 B. Inductor

 C. Series resonant circuit

 D. Parallel resonant circuit

320. What is the characteristic impedance of a coaxial line, air dielectric with a ratio of the diameter of the outer and inner conductor equal to 1.5?

 A. 24.3 ohms

 B. 25.6 ohms

 C. 13.2 ohms

 D. 18 ohms

321. Currents that flow in opposite direction in a balanced wire pair is called

 A. Longitudinal currents

 B. Reverse circuit currents

 C. Transverse circuit currents

 D. Metallic circuit currents 322. Currents that flow in same direction in a balanced wire pair is called

 A. Longitudinal currents

 B. Reverse circuit currents

 C. Transverse circuit currents

 D. In-phase currents

323. A circuit device used to connect a balanced transmission line to an unbalanced load

 A. Slotted lines

 B. Stub

 C. Balun

 D. Quarterwave lines

324. The most common type of balun used in relatively high frequency

 A. Narrowband

 B. Choke

 C. Sleeve

 D. All of these

325. A pattern of voltage and current variations along the transmission line not terminated in its characteristic impedance is called

 A. An electric fluid

 B. Radio waves

 C. Standing waves

 D. A magnetic field

326. A type of parallel-conductor transmission lines consists of simply of two parallel wires, closely- spaced and separated by air.

 A. Twisted pair

 B. Open-wire lines  C. Coaxial cables

 D. Twin pair

327. A type of parallel-conductor transmission lines which is essentially the same as open-wire transmission line except that the spacers between the conductors are replaced with a continuous solid dielectric that ensures uniform spacing along the entire cable

 A. Twisted pair

 B. Open-wire lines

 C. Coaxial cables

 D. Twin lead

328. What is the range of size of wires of a twisted pair?

 A. AWG 16 to AWG 26

 B. AWG 14 to AWG 25

 C. AWG 10 to AWG 20

 D. AWG 12 to AWG 28

329. What is the characteristic impedance of a coaxial line, polyethylene dielectric with the ratio of the diameter of the outer and the inner conductor of 2.5?

 A. 43.5 ohms

 B. 23.4 ohms

 C. 36.2 ohms

 D. 29.8 ohms

330. In AWG, the higher the wire gauge ______

 A. The higher the diameter and the lower the resistance

 B. The smaller the diameter and the higher the resistance

 C. The smaller the diameter and the higher the conductance

 D. The larger the diameter and the higher the resistance

331. Type of twisted pair wire cable that consists of two copper wires where each wire is separately encapsulated in PVC insulation.  A. Shielded twisted pair

 B. Twin lead

 C. Unshielded twisted pair

 D. Open wire frame

332. A shorted quarter-wave line at the operating frequency acts like

 A. Series resonant circuit

 B. Parallel resonant circuit

 C. Capacitor

 D. Inductor

333. The minimum number of twist for UTP is

 A. Two twist per foot

 B. Two twist per meter

 C. Three twist per foot

 D. Three twist per meter

334. A delay line using RG-8A/U cable is to exhibit a 5-ns delay. Calculate the required length of the cable.

 A. 4.57 ft.

 B. 1.23 ft.

 C. 6.2 ft.

 D. 3.4 ft.

335. An open-circuited quarter-wavelength line acts like a

 A. Parallel resonant circuit

 B. Series resonant circuit

 C. Oscillator

 D. LC circuit 336. Level for category of UTP cable which is suitable only for voice grade telephone signals and very low-speed data applications

 A. Level 1 or Cat 1

 B. Level 3 or Cat 3

 C. Level 2 or Cat 2

 D. Cat 4

337. An antenna is being fed by a properly terminated two-wire transmission line. The current in the line at the input end is 3 A. The surge impedance of the line is 500 ohms. How much power is being supplied to the line?

 A. 3.1 kW

 B. 2.5 kW

 C. 1.6 kW

 D. 4.5 kW

338. Level or Category of UTP cable which was developed for IEEE 802.5 token ring local area networks operating at a transmission rates of 4Mbps

 A. Level 1 or Cat 1

 B. Level 3 or Cat 3

 C. Level 2 or Cat 2

 D. Cat 4

339. If the period of one complete cycle of a radio wave is 0.000001 s, what is the wavelength?

 A. 300 m

 B. 200 m

 C. 100 m

 D. 400 m

340. If the two towers of a 950-kHz antenna are separated by 120 electrical degrees, what is the tower separation in feet?

 A. 231 ft.  B. 235 ft.

 C. 176 ft.

 D. 345 ft.

341. Category of UTP used for virtually any voice or data transmission rate up to 16 Mbps, has a minimum of 3 turns per inch.

 A. Category 5e

 B. Category 4

 C. Category 5

 D. Category 3

342. The mismatch between the antenna and transmission line impedances cannot be corrected for by

 A. Using an LC matching network

 B. Adjusting antenna length

 C. Using a balun

 D. Adjusting the length of transmission line

343. Category of UTP that was designed for data transmission rates up to 20 Mbps

 A. Category 5e

 B. Category 4

 C. Category 5

 D. Category 3

344. Variation of CAT5 cables that are intended for data transmission rates up to 250 Mbps

 A. Category 5e

 B. Category 2

 C. Category 6

 D. Category 3 345. A type of twisted-pair wherein its wires and dielectric are enclosed in a conductive metal sleeve called a foil.

 A. STP

 B. Twin lead

 C. UTP

 D. Unshielded Twin lead

346. It is the name given to the area between the ceiling and the roof in a single-story building or between the ceiling and the floor of the next higher level in a multistory building.

 A. Attic

 B. Rooftop

 C. Plenum

 D. Ceiling

347. It consists of center conductor surrounded by dielectric material, then a concentric shielding, and an environmental protection outer jacket.

 A. Twisted pair

 B. Coaxial cable

 C. Twin lead

 D. Open wire

348. In a transmission line, it refers to the woven stranded mesh or braid that surround some types of coaxial cables

 A. Grounding

 B. Shielding

 C. Degaussing

 D. Any of these

349. A coaxial cable with one layer of foil insulation and one layer of braided shielding.

 A. Backup shielding

 B. Temporary shielding  C. Dual shielding

 D. Interference shielding

350. At very high frequencies, transmission lines are used as

 A. Tuned circuits

 B. Antennas

 C. Insulators

 D. Resistors

301. Guided 327. Twin lead 302. Transmission Lines 328. AWG 16 to AWG 26 303. 51.6 ohms 329. 36.2 ohms 304. Unguided 330. The smaller the diameter and the 305. Transmission medium higher the resistance 306. Transmission line 331. Unshielded twisted pair 307. Longitudinal 332. Parallel resonant circuit 308. 22 pF 333. Two twist per foot 309. 1 334. 3.4 ft. 310. Transverse 335. Series resonant circuit 311. Series Resonant Circuit 336. Level 1 or Cat 1 312. Incident waves 337. 4.5 kW 313. Reflected waves 338. Level 2 or Cat 2 314. 1100 feet per second 339. 300 m 315. 215 ohms 340. 345 ft. 316. Frequency 341. Category 3 317. Wavelength 342. Adjusting the length of 318. Differential transmission lines transmission line 319. Series resonant circuit 343. Category 4 320. 24.3 ohms 344. Category 5e 321. Metallic circuit currents 345. STP 322. Longitudinal currents 346. Plenum 323. Balun 347. Coaxial cable 324. All of these 348. Shielding 325. Standing waves 349. Dual shielding 326. Open-wire lines 350. Tuned circuits 351. A coaxial cable with two layers of foil insulation and two layers of braided shielding.

 A. Quad shielding

 B. Double shielding

 C. Triple shielding

 D. Shielding

352. A type of coaxial cable that has a tubular outer conductor surrounds the center conductor coaxially and the insulating material is air.

 A. Rigid air coaxial cable

 B. Gas-filled coaxial cable

 C. Solid coaxial cable

 D. Flexible cable

353. If the length of an open-circuited stub is less than quarter-wavelength but greater than 0, the stub behaves as

 A. Inductor

 B. Capacitor

 C. Resistor

 D. Complex

354. Type of coaxial cable where the outer conductor is braided, flexible, and coaxial to the center conductor.

 A. Gas-filled coaxial cable

 B. Rigid air coaxial cable

 C. Solid flexible coaxial cable

 D. Flexible cable

355. A 50-ohm coax is connected to a 73-ohm antenna. The SWR is

 A. 0.685  B. 1

 C. 1.46

 D. 2.92

356. Defined as the impedance seen looking at an infinitely long line or the impedance seen looking into a finite length of the line that is terminated in a purely resistive load with the resistance equal to the characteristic impedance of the line.

 A. Input impedance

 B. Surge impedance

 C. Output impedance

 D. Circuit impedance

357. Determine the characteristic impedance for an air dielectric two-wire parallel transmission line with a D/r ratio of 12.22

 A. 150 ohms

 B. 120 ohms

 C. 75 ohms

 D. 300 ohms

358. Determine the characteristic impedance for an RG-59A coaxial cable with the following specifications: d = 0.025 inches, D = 0.15 inches, and dielectric constant of 2.23

 A. 120 ohms

 B. 72 ohms

 C. 150 ohms

 D. 75 ohms

359. Determine the characteristic impedance for an RG-59A coaxial cable with the following specifications: L=0.118 uH/ft and C = 21 pF/ft

 A. 150 ohms

 B. 72 ohms

 C. 75 ohms  D. 100 ohms

360. It is used to express the attenuation or signal loss and the phase shift per unit length of the transmission line.

 A. Propagation coefficient

 B. Propagation constant

 C. Propagation factor

 D. Any of these

361. For matched condition, what is the relationship of load and characteristic impedance?

 A. Greater than

 B. Less than

 C. Equal

 D. Impossible to say

362. It is defined simply as the ratio of the actual velocity of propagation of an electromagnetic wave through a given medium to the velocity of propagation through a vacuum or free space.

 A. Velocity factor

 B. Velocity propagation

 C. Index of refraction

 D. Phase delay

363. It is simply the permittivity of the material

 A. Permittivity

 B. Insulation constant

 C. Dielectric constant

 D. Resistivity

364. For a given length of RG 8A/U coaxial cable with distributed capacitance of 96.6 pF/m, a distributed inductance of 241.56 nH/m, and a relative dielectric constant of 2.3, determine the velocity of propagation.

 A. 1.07 x 10^8 m/s  B. 2.3 x 10^7 m/s

 C. 3.28 x 10^8 m/s

 D. 2.07 x 10^8 m/s

365. For a given length of RG 8A/U coaxial cable with distributed capacitance of 96.6 pF/m, a distributed inductance of 241.56 nH/m, and a relative dielectric constant of 2.3, determine the velocity factor

 A. 1.2

 B. 0.66

 C. 0.7

 D. 0.5

366. If the length of an open-circuited stub is greater than quarter-wavelength but less than half- wavelength, the stub behaves as

 A. Inductor

 B. Capacitor

 C. Resistor

 D. Complex

367. Delay line is a function of what two parameters?

 A. Resistance and capacitance

 B. Resistance and susceptance

 C. Inductance and resistance

 D. Inductance and capacitance

368. How is the time delay calculated in a coaxial cables with a dielectric constant of 0.66?

 A. 0.56 sec

 B. 0.67 sec

 C. 0.45 sec

 D. 1.2 sec 369. Three feet is one wavelength at a frequency of

 A. 100 MHz

 B. 164 MHz

 C. 300 MHz

 D. 328 MHz

370. When current flows through a conductor, the loss introduced as a function of resistance and current is called ______.

 A. Inductance loss

 B. Conductor loss

 C. Voltage loss

 D. Skin effect

371. For maximum absorption of power at the antenna, the relationship between the characteristic impedance of the line Zo and the load impedance ZL should be

 A. Zo = ZL

 B. Zo > ZL

 C. Zo < ZL

 D. Zo = 0

372. The ratio of the AC resistance and the DC resistance.

 A. Impedance ratio

 B. Susceptance ratio

 C. Resistance ratio

 D. Conductance ratio

373. The difference in potential between two conductors of a metallic transmission line causes ______.

 A. Conductor loss

 B. Dielectric heating  C. Radiation loss

 D. Corona

374. If the length of a short-circuited stub is greater than quarter-wavelength but less than half- wavelength, the stub behaves as

 A. Inductor

 B. Capacitor

 C. Resistor

 D. Complex

375. If the separation between the conductors in a metallic transmission line is an appreciable fraction of a wavelength, the electrostatic and electromagnetic fields that surround the conductor cause the line to act as if it were an antenna and transfer energy to any nearby material. This energy radiated is called ______.

 A. Radiation loss

 B. Power loss

 C. Coupling loss

 D. Corona

376. The minimum voltage along a transmission line is 260 V, while the maximum is 390 V. The SWR is

 A. 0.67

 B. 1.0

 C. 1.2

 D. 1.5

377. It occurs whenever a connection is made to or from a transmission line or when two sections of transmission line are connected together.

 A. Power loss

 B. Coupling loss

 C. Radiation loss

 D. Resistance loss 378. Which of the following is not a common transmission line impedance?

 A. 50 ohms

 B. 75 ohms

 C. 120 ohms

 D. 300 ohms

379. It is a luminous discharge that occurs between the two conductors of a transmission line when the difference in potential between them exceeds the breakdown voltage of a dielectric insulator.

 A. Resistance loss

 B. Corona

 C. Radiation loss

 D. Power loss

380. Voltage that propagates down the load.

 A. Reflected voltage

 B. Standing wave ratio

 C. Incident voltage

 D. Reflection voltage

381. Voltage that propagates from the load towards the source.

 A. Reflected voltage

 B. Standing wave ratio

 C. Reflection coefficient

 D. Incident voltage

382. A transmission line with no reflected power.

 A. Flat

 B. Resistive

 C. Non resonant line  D. Any of these

383. It is a vector quantity that represents the ratio of reflected voltage to incident voltage or the reflected current and the incident current

 A. Reflection coefficient

 B. Reactive load diagram

 C. Standing wave ratio

 D. Traveling waves

384. With a mismatched line, two electromagnetic waves traveling in opposite direction, present on the line on the same time.

 A. Standing wave ratio

 B. Reflection coefficient

 C. Standing waves

 D. Traveling waves

385. The two traveling waves sets up an interference pattern called ______.

 A. Standing wave ratio

 B. Reflection coefficient

 C. Standing waves

 D. Traveling waves

386. It is defined as the ratio of the maximum voltage to the minimum voltage or the maximum current to the minimum current of a standing wave in a transmission line.

 A. Standing wave ratio

 B. Normalized impedance

 C. Reflection coefficient

 D. Any of these

387. For a transmission line with an incident voltage of 5V and a reflected voltage of 3V, determine the reflection coefficient.

 A. 0.4  B. 0.6

 C. 0.5

 D. 0.7

388. A ratio expressing the percentage of incident voltage reflected on a transmission line is known as the

 A. Velocity factor

 B. Standing wave ratio

 C. Reflection coefficient

 D. Line efficiency

389. There is an impedance inversion in every ______.

 A. Half wavelength

 B. Quarter wavelength

 C. Full wavelength

 D. Three-eights of a wavelength

390. The characteristic impedance of a transmission line does not depend upon its

 A. Length

 B. Conductor diameter

 C. Conductor spacing

 D. None of these

391. ______are used to match transmission lines to purely resistive loads whose resistance is not equal to the characteristic impedance of the line.

 A. Stub

 B. Slotted lines

 C. Quarter-wavelength transformer

 D. Short circuited lines

392. To match a transmission line with a reactive load ______.  A. Use stub matching

 B. Use a slotted line

 C. Used a Q-section

 D. Use an open circuited lines

393. A technique that can be used to locate an impairment in metallic cable.

 A. TDR

 B. Wattmeter

 C. Voltmeter

 D. SWR meter

394. A pulse is transmitted down a cable that has a velocity of propagation of 0.8c. The reflected signal is received 1us later. How far down the cable is the impairment?

 A. 240 m

 B. 15 m

 C. 60 m

 D. 120 m

395. Using TDR, a transmission line impairment is located 3000m from the source. For a velocity propagation of 0.9 c, determine the time elapsed from the beginning of the pulse to the reception of the echo

 A. 11.11 us

 B. 10.12 us

 C. 22.22 us

 D. 21.14 us

396. A flat conductor separated from a ground plane by an insulating dielectric material.

 A. Stripline

 B. Waveguide

 C. Microstrip  D. Coaxial cable

397. A flat conductor sandwich between two ground planes.

 A. Stripline

 B. Waveguide

 C. Microstrip

 D. Coaxial cable

398. Indicate the false statement. The SWR on a transmission line is infinity; the line is terminated in

 A. A short circuit

 B. A complex impedance

 C. An open circuit

 D. A pure reactance

399. The most commonly used transmission line is a

 A. Two-wire balance line

 B. Singe wire

 C. Three-wire line

 D. Coax

400. A short-circuited half-wavelength line acts like a

 A. Parallel resonant circuit

 B. Series resonant circuit

 C. Oscillator

 D. LC circuit

351. Quad shielding 357. 300 ohms 352. Rigid air coaxial cable 358. 72 ohms 353. Capacitor 359. 75 ohms 354. Solid flexible coaxial cable 360. Any of these 355. 1.46 361. Equal 356. Surge impedance 362. Velocity factor 363. Dielectric constant 382. Any of these 364. 2.07 x 10^8 m/s 383. Reflection coefficient 365. 0.66 384. Traveling waves 366. Inductor 385. Standing waves 367. Inductance and capacitance 386. Standing wave ratio 368. 0.67 sec 387. 0.6 369. 328 MHz 388. Reflection coefficient 370. Conductor loss 389. Quarter wavelength 371. Zo = ZL 390. Length 372. Resistance ratio 391. Quarter-wavelength transformer 373. Dielectric heating 392. Use stub matching 374. Capacitor 393. TDR 375. Radiation loss 394. 120 m 376. 1.5 395. 22.22 us 377. Coupling loss 396. Microstrip 378. 120 ohms 397. Stripline 379. Corona 398. A complex impedance 380. Incident voltage 399. Coax 381. Reflected voltage 400. Series resonant circuit

401. A (75 - j50)-ohm is connected to a coaxial transmission line of Zo = 75 ohms, at 10 GHz. The best method of matching consists of connecting

 A. A short-circuited stub at the load

 B. An inductive at the load

 C. A capacitance at some specific distance from the load

 D. A short-circuited stub at some specific distance from the load

402. The velocity factor of a transmission line

 A. Depends on the dielectric constant of the material used

 B. Increases in velocity along the transmission line

 C. Is governed by the skin effect

 D. Is higher for a solid dielectric than for air.

403. Impedance inversion may be obtained with

 A. A short-circuited stub  B. An open-circuited stub

 C. A quarter-wave line

 D. A half-wave line

404. The most desirable reflection coefficient is

 A. 0

 B. 0.5

 C. 1

 D. Infinity

405. Short circuited stubs are preferred to open-circuited stub because the latter are

 A. More difficult to make and connect

 B. Made of a transmission line with different characteristic impedance

 C. Liable to radiate

 D. Incapable of giving a full range of reactance

406. For transmission-line load matching over a range of frequencies, it is best to use a

 A. Balun

 B. Broadband directional coupler

 C. Double stub

 D. Single stub of adjustable position

407. The main disadvantage of the two-hole directional coupler is

 A. Low directional coupling

 B. Poor directivity

 C. High SWR

 D. Narrow bandwidth

408. To couple a coaxial line to a parallel-wire line, it is best to use a  A. Slotted line

 B. Balun

 C. Directional coupler

 D. Quarter-wave transformer

409. A short-circuited quarter-wavelength line acts like a

 A. Parallel resonant circuit

 B. Series resonant circuit

 C. Oscillator

 D. LC circuit

410. If the length of a short-circuited stub is less than a quarter-wavelength but greater than 0, the stub behaves as

 A. Inductor

 B. Capacitor

 C. Resistor

 D. Complex

411. The depth of penetration of current density resulting from skin effect

 A. Skin depth

 B. Wire depth

 C. Line depth

 D. Medium depth

412. Transmission line must be matched to the load to

 A. Transfer maximum voltage to the load

 B. Transfer maximum current to the load

 C. Reduce the load current

 D. Transfer maximum power to the load 413. Referred to the dielectric constant of a transmission line material

 A. Inductance and capacitance

 B. Velocity factor

 C. Characteristic impedance

 D. Propagation velocity

414. A transmission line containing of two conductors that have equal resistance per unit length

 A. Unbalanced line

 B. Open-wire line

 C. Balanced line

 D. Coaxial cable

415. Which of the following determines the characteristics of a transmission line?

 A. Inductance

 B. Capacitance

 C. Physical dimension

 D. Length

416. Category of UTP that was designed for data transmission rates up to 20 Mbps

 A. Category 5e

 B. Category 4

 C. Category 5

 D. Category 3

417. Level 2 or category 2 UTP cables comply with IBM’s ______specification.

 A. Type 1

 B. Type 3

 C. Type 2  D. Type 4

418. Level 3 or Category 3 UTP cables should have at least ____ twist per inch.

 A. 1

 B. 2

 C. 3

 D. 4

419. Which of the following is NOT a color code for Category 5 UTP?

 A. Blue/white stripe and blue

 B. Orange/white stripe and orange

 C. Red/white stripe and red

 D. Brown/white stripe and brown

420. Shielded-screen twisted-pair cable or SSTP is also known as ______.

 A. Cat 5e

 B. Cat 7

 C. Cat 6

 D. Cat 8

421. An open-circuited transmission line quarter wavelength long is equivalent to

 A. Parallel resonant circuit

 B. Series resonant circuit

 C. Inductive

 D. Capacitive

422. A short-circuited transmission line more than quarter-wavelength long but shorter than half wavelength is equivalent to ______.

 A. Series resonant circuit

 B. Inductive  C. Capacitive

 D. Parallel resonant circuit

423. A short-circuited transmission line less than quarter-wavelength long.

 A. Inductive

 B. Capacitive

 C. Parallel resonant circuit

 D. Series resonant circuit

424. The quarter-wavelength transformer line acts as a transformer with a 1:1 turns ratio when the load resistance is with what relationship with the characteristic impedance of the quarter-wavelength transformer?

 A. Equal

 B. Less than

 C. Greater than

 D. None of these

425. The characteristic impedance of a microstrip is equal to _____ ohms.

 A. 50 to 200

 B. 25 to 50

 C. 100 to 200

 D. 50 to 75

426. The quarter-wavelength transformer line acts as a step down transformer when the load resistance is with what relationship with the characteristic impedance of the quarter-wavelength transformer?

 A. Equal

 B. Less than

 C. Greater than

 D. None of these

427. The typical value of the velocity factor of an open-wire transmission line is  A. 0.8

 B. 0.7

 C. 0.6

 D. 0.9

428. If a transmission line is not terminated in its characteristic impedance, ______will develop along the line.

 A. Traveling waves

 B. Standing waves

 C. Surge impedance

 D. Infinite impedance

429. If a load and a line have mismatched impedances, power not absorbed by the load will be _____.

 A. Absorbed

 B. Rejected

 C. Reflected

 D. Removed

430. Two wire line is usually operated in the:

 a. Balanced mode

 b. Unbalanced mode

 c. High frequency

 d. None of these

431. When the load impedance doesn’t not match the line impedance, part of the energy in the incident wave is ______at the load.

 a. Forwarded

 b. Reflected

 c. Same  d. None of these

432. In practice, the transmission lines are almost connected to antennas that have a _____.

 a. Resistive load whose resistance is greater than the characteristic impedance of the line

 b. Resistive load whose resistance is less than the characteristic impedance of the line

 c. Resistive load at the resonant frequency

 d. Capacitive load

433. When the transmission line is matched to the load, it

 a. Transfers maximum current to the load

 b. Transfers maximum voltage to the load

 c. Transfers maximum power to the load

 d. Reduces the load current

434. Conventional transmission media include

 a. Twisted cable pair

 b. Waveguide

 c. Fiber optic cable

 d. All of these

435. To couple a coaxial line to a parallel wire line, it is best to use a _____

 a. Slotted line

 b. Directional coupler

 c. Balun

 d. All of these

436. Impedance inversion may be obtained with

 a. An open circuited stub

 b. A short circuited stub  c. A quarterwave line

 d. A half-wave line

437. To be properly matched, the ratio of maximum to minimum voltage along a transmission line should be equal to

 a. 50

 b. 10

 c. 2

 d. 1

438. When ZL ≠ Zo, the power sent down the line toward the load is called the

 a. The incident power

 b. The reflected power

 c. The power dissipation

 d. The carrier power

439. For transmission line load matching over a range of frequencies, it is best to use a

 a. Balun

 b. Broadband directional coupler

 c. Double stub

 d. Single adjustable stub

440. A short section of a transmission line, open or shorted that is used to match the impedance of the line to that of an antenna or transmitter.

 a. Slotted line

 b. Stub

 c. Wavetrap

 d. Lecher wire

441. The property of a material that determines how much electrostatic energy can be stored per unit volume when voltage is applied  a. Permeability

 b. Magnetic effect

 c. Capacitance

 d. Permittivity

442. The value of the total opposition of the transmission media to the flow of electromagnetic field energy is called

 a. Characteristic impedance

 b. Velocity factor

 c. Standing waves

 d. Reflected waves

443. When mismatch is great, this power actually cause damage to the transmitter or the line itself.

 a. The incident power

 b. The reflected power

 c. The power dissipation

 d. The carrier power

444. What is the velocity factor for non-foam dielectric 50 or 75 ohm flexile coaxial cable such as RG 8, 11, 58 and 59?

 a. 270

 b. 0.10

 c. 0.66

 d. 0.30

445. The measure of the superiority of a material over a vacuum as a path for magnetic lines of force is

 a. Permittivity

 b. Permeability

 c. Conductivity  d. Resistivity

446. The number of standing waves on the wire is equal to the length of the wire divided by a half wavelength. The principle which allows antennas to operate at different frequencies which are integral multiples of the fundamental frequency is called______.

 a. Harmonic operation

 b. Decimonic operation

 c. Electromagnetic reverberation

 d. Asynchronous operation

447. A coax line has an attenuation of 2.4 dB per 100 ft. the attenuation for 2.75 ft. is _____ dB.

 a. 2.4

 b. 4.8

 c. 3.3

 d. 6.6

448. When a quarter wave stub is used to match a 600 ohm antenna to a line of 52 ohms, the impedance of the matching stub must be ____ ohms.

 a. 176

 b. 200

 c. 150

 d. 300

449. The characteristic impedance of a transmission line is determined by

 a. Its length

 b. Its height above ground

 c. Its physical construction

 d. The operating frequency

450. When the diameter of two conductors of a two-wire transmission line is held constant, the effect of decreasing the distance between the conductors is to

 a. Decrease the impedance  b. Increase the surge impedance

 c. Increase the radiation resistance

 d. Decrease SWR

401. A short-circuited stub at some 426. Greater than specific distance from the load 427. 0.8 402. Depends on the dielectric 428. Standing waves constant of the material used 429. Reflected 403. A quarter-wave line 430. Balanced mode 404. 0 431. Reflected 405. Liable to radiate 432. Resistive load whose resistance is 406. Double stub less than the characteristic impedance 407. Narrow bandwidth of the line 408. Balun 433. Transfers maximum power to the 409. Parallel resonant circuit load 410. Inductor 434. All of these 411. Skin depth 435. Balun 412. Transfer maximum power to the 436. A quarterwave line load 437. 1 413. Inductance and capacitance 438. The incident power 414. Balanced line 439. Double stub 415. Physical dimension 440. Stub 416. Category 4 441. Permittivity 417. Type 3 442. Characteristic impedance 418. 3 443. The reflected power 419. Red/white stripe and red 444. 0.66 420. Cat 7 445. Permeability 421. Series resonant circuit 446. Harmonic operation 422. Capacitive 447. 6.6 423. Inductive 448. 176 424. Equal 449. Its length 425. 50 to 200 450. Decrease the impedance 451. Considering a coaxial transmission line, maximum voltage on the line divided by the minimum voltage equals the

 a. Characteristic impedance

 b. ISWR

 c. VSWR

 d. Inductive reactance

452. In a transmission line, if the SWR or maximum current to a minimum current ratio of 2:1, the ratio of the maximum voltage to the minimum voltage is

 a. 1:4

 b. 4:1

 c. 1:2

 d. 2:1

453. Transmission lines are either balanced or unbalanced with respect to

 a. Negative terminal

 b. Input

 c. Ground

 d. Positive terminal

454. The load is properly matched with the transmission line if the standing wave ratio is equal to

 a. 50

 b. 10

 c. 5

 d. 1

455. The radiation resistance of a quarterwave antenna is

 a. 49 ohms  b. 288 ohms

 c. 72 ohms

 d. 144 ohms

456. A radio transmission line of 500 ohms impedance is to be connected to an antenna having an impedance of 200 ohms. What is the impedance of a quarter wave matching line?

 a. 300

 b. 316

 c. 316.5

 d. 361

457. The VSWR for a line terminated in its Zo is

 a. 0

 b. 1

 c. 1.5

 d. Infinity

458. Which of the following is used to measure SWR?

 a. Multimeter

 b. Reflectometer

 c. Spectrum analyzer

 d. Oscilloscope

459. A 75 – j50 ohm load is connected to a coaxial transmission line of Zo = 75 ohms at 10 GHz. The best method of matching consists in connecting

 a. A short circuited stub at the load

 b. A capacitance at some specific distance from the load

 c. An inductance at the load

 d. A short-circuited stub at some specific distance from the load 460. For a two-wire line, Zo is higher when

 a. The wire size is small with respect to the spacing of the conductors

 b. The spacing is varied in accordance with the frequency

 c. The D:d ratio is smaller

 d. The wire is large with respect to the spacing of the conductors

461. A resultant wave due to the combination of incident and reflected wave

 a. Electromagnetic wave

 b. Sine wave

 c. Standing wave

 d. Current

462. For transmission line load matching over a range of frequencies, it is best to use a

 a. Balun

 b. Broadband directional coupler

 c. Double stub

 d. Single stub

463. If the load impedance matches the characteristic impedance of the line, there are _____ standing waves.

 a. More

 b. Less

 c. No

 d. Ten(10)

464. VSWR stands for

 a. Voltage sending wave ratio

 b. Voltage receiving wave ratio

 c. Very small wave radiation  d. Voltage standing wave ratio

465. Reflections on a transmission line can occur when

 a. Impedance of the source and load are matched

 b. Impedance of the source and the load are mismatched

 c. Resonance conditions are obtained

 d. Power transfer between source and load is maximum

466. A transmission line with characteristic impedance (Zo) of 300 ohms is terminated in a resistance load (RI). If by measurement, the minimum and maximum voltage through the load are 12 and 20 micro volts, respectively, what is the SWR?

 a. 1.67

 b. 0.6

 c. 6.7

 d. 3.67

467. A measure of the mismatched between line and load impedance is called as

 a. Reflection coefficient

 b. Standing wave ratio

 c. Loss

 d. Standing waves

468. Transmission lines when connected to antenna have

 a. Capacitive load

 b. Resistive load whose resistance is less than characteristic impedance

 c. Resistive load at the resonant frequency

 d. Resistive load whose resistance is greater than the characteristic impedance of the line

469. At matched condition, SWR is equal to

 a. Zero  b. One

 c. 100

 d. Infinite

470. An HF transmission line has a characteristic impedance of 600 ohms and is terminated by an antenna. The SWR along the line when the antenna impedance is 500 ohms is

 a. 1.2:1

 b. 1:2.1

 c. 2:1

 d. 1:2

471. A characteristic of an infinite transmission line is that

 a. The impedance in equals impedance out

 b. It carries waves at the velocity of light

 c. It can be connected to mismatched loads

 d. The impedance varies with the length of the line

472. A quarter wave transmission line shorted at the end:

 a. Has the characteristics of parallel tuned circuit

 b. Has the characteristics of a series tuned circuit

 c. Has a minimum current at the end

 d. Reflects a low impedance to the supply

473. The outer conductor of a coaxial transmission line is usually grounded at the:

 a. Input and output

 b. Output only

 c. Input only

 d. Point of infinite resistance

474. A certain feedline has a high SWR. It can be caused by:  a. An impedance mismatched

 b. Use of non-resonant line

 c. Matching the load to the line

 d. Excessive transmitter output

475. If the input impedance of an antenna is 300 ohms and it is fed with a 600 ohm balanced transmission line, the SWR on the line is

 a. 4

 b. 3

 c. 2

 d. 0.5

476. A radio transmission line of 300 ohms impedance to be connected to an antenna having an input impedance of 150 ohms. The impedance if a quarter wave matching line is ___ ohms

 a. 212

 b. 450

 c. 600

 d. 150

477. The ratio of the reflected voltage to the incident voltage on the transmission line is termed as

 a. Reflection coefficient

 b. Standing wave ratio

 c. Loss

 d. Standing waves

478. Indicate the three types of transmission line energy losses

 a. Radiation, I2R and dielectric Heating

 b. Conductor heating, dielectric heating and radiation resistance

 c. I2R, RL and temperature  d. Dielectric separation insulation breakdown and radiation

479. Termination means

 a. Load connected to the output end of a transmission line

 b. Result of disconnecting a line from a transmitter

 c. Looking back impedance of a line with no load

 d. Result of cutting both ends of a conductor

480. When transmission line uses ground return, it is called a/n _____ line.

 a. Ungrounded

 b. Unbalanced

 c. Grounded

 d. Balanced

481. Permeability is the measure of superiority of a material over a vacuum as a path of magnetic lines of force. The permeability of free space is equal to _____ henry/meter

 a. 1.257 x 10-6

 b. 1.527 x 10-6

 c. 7.251 x 10-6

 d. 5.217x10-6

482. The most commonly used transmission line is a

 a. Two-wire balanced line

 b. Single line

 c. Three-wire line

 d. Coax

483. The characteristic impedance of a transmission line does not depend upon its

 a. Length

 b. Conductor diameter  c. Conductor spacing

 d. Thickness of armor

484. What is the impedance of a balance 4-wire with a diameter of 0.25cm and spaced 2.5 cm apart using an insulator with a dielectric constant of 2.56?

 a. 100 ohms

 b. 65 ohms

 c. 75 ohms

 d. 50 ohms

485. It is required to match a 73-ohm antenna to a 600 ohm polyethylene coaxial feeder line, with a velocity factor of 0.66 by means of a quarter wave matching a transformer. At a frequency of 150 MHz, the impedance of the matching section is____ ohms.

 a. 209.28

 b. 310.5

 c. 150.28

 d. 450.82

486. If the terminating impedance is exactly equal to the characteristic impedance of the transmission line, the return loss is____

 a. Zero

 b. Infinity

 c. One

 d. Negative

487. The characteristic impedance of a transmission line is the impedance measured at the ____ when its length is infinite.

 a. Shorted end of the line

 b. Midsection

 c. Input

 d. Output 488. The characteristic impedance of a transmission line is 70 ohms and has a load of 35 ohms. The SWR and reflection coefficient are _____ and _____ respectively

 a. 2 and 0.333

 b. 1 and 0.666

 c. 2 and 0.666

 d. 1 and 0.333

489. It is required to match a 200 ohm load to a 300 ohm transmission line to reduce the SWR and attain resonance. A quarter wave transformer used, directly connected to the load has a Zo of ____ ohms.

 a. 245

 b. 425

 c. 524

 d. 254

490. What quarter wave transformer will match a 100 ohm-line to an antenna whose value is 175 ohms?

 a. 150 ohms

 b. 137.5 ohms

 c. 132.29 ohms

 d. 16.58 ohms

491. The mismatch between antenna and transmission line impedance cannot be corrected by

 a. Using an LC network

 b. Adjusting antenna length

 c. Using a balun

 d. Adjusting the length of the transmission line

492. A pattern of voltage and current variation along a transmission line not terminated in its characteristic impedance is called

 a. An electric field

 b. Radio waves  c. Standing waves

 d. Magnetic field

493. The most desirable value of SWR on a transmission line is

 a. 0

 b. 1

 c. 2

 d. Infinity

494. In transmission lines, the most desirable reflection coefficient is

 a. Zero

 b. 0.5

 c. 1

 d. Infinity

495. At very high frequencies, transmission lines are used as _____.

 a. Tuned circuits

 b. Antennas

 c. Insulators

 d. Resistors

496. What is the reflection coefficient of a 100 ohm characteristic impedance line and a 300 ohm load?

 a. 0.25

 b. 0.3

 c. 0.5

 d. 0.75

497. The minimum voltage along a transmission line is 260 volts, while the maximum is 390 volts. The SWR is

 a. 0.67  b. 1.0

 c. 1.2

 d. 1.5

498. A single conductor running from the transmitter to the antenna

 a. RG-8/U

 b. Single line wire

 c. Twin-lead

 d. Microstrip

499. What characteristic impedance is needed to match a 50-ohm line to a 300 ohm-load?

 a. 221 ohms

 b. 122 ohms

 c. 212 ohms

 d. 112 ohms

500. Indicate the false statement. The SWR on a transmission line is infinity; the line is terminated in

 a. Short circuit

 b. A complex impedance

 c. An open circuit

 d. A pure reactance

451. VSWR 460. The wire size is small with respect 452. 2:1 to the spacing of the conductors 453. Ground 461. Standing wave 454. 1 462. Double stub 455. 72 ohms 463. No 456. 316 464. Voltage standing wave ratio 457. 1 465. Impedance of the source and the 458. Reflectometer load are mismatched 459. A short-circuited stub at some 466. 1.67 specific distance from the load 467. Standing wave ratio 468. Resistive load at the resonant 483. Thickness of armor frequency 484. 100 ohms 469. One 485. 209.28 470. 1.2:1 486. Zero 471. The impedance in equals 487. Input impedance out 488. 2 and 0.333 472. Has the characteristics of parallel 489. 245 tuned circuit 490. 132.29 ohms 473. Input and output 491. Using an LC network 474. An impedance mismatched 492. Standing waves 475. 2 493. 1 476. 212 494. Zero 477. Reflection coefficient 495. Tuned circuits 478. Radiation, I2R and dielectric Heating 496. 0.5 479. Load connected to the output end 497. 1.5 of a transmission line 498. Single line wire 480. Unbalanced 499. 122 ohms 481. 1.257 x 10-6 500. A complex impedance 482. Two-wire balanced line

501. A (75 – j50) Ω load is connected to a coaxial transmission line of Zo = 75 Ω at 10 GHz. The best method of matching consists in connecting

 a. A short circuited stub

 b. An inductance at the load

 c. A capacitance at some specific distance from the load

 d. A short circuited stub at some specific distance from the load

502. The velocity factor of a transmission line

 a. Depends on the dielectric constant of the material used

 b. Increases the velocity along the transmission line

 c. Is governed by the skin effect

 d. Is higher for a solid dielectric than for air 503. What is the characteristic impedance of a single wire with diameter d = 0.25 mm placed at the center between grounded parallel planes separated by 1mm apart. The wire is held by a material with a velocity factor of 0.75

 a. 85 ohms

 b. 63 ohms

 c. 50 ohms

 d. 75 ohms

504. Coaxial lines are used on those system operating ______.

 a. Below 2 GHz

 b. At 300 MHz

 c. Above 10 KHz

 d. Above 10 GHz

505. Referred to the dielectric constant of a transmission line material

 a. Inductance and capacitance

 b. Velocity factor

 c. Characteristic impedance

 d. Propagation velocity

506. The main advantage of the two-hole directional coupler is

 a. Low directional coupling

 b. Poor directivity

 c. High SWR

 d. Narrow bandwidth

507. To couple a coaxial line to a parallel-wire line, it is best to use a

 a. Slotted line

 b. Balun  c. Directional coupler

 d. Quarter-wave transformer

508. What is the meaning of the term velocity factor of a transmission line?

 a. The index of shielding for coaxial cable

 b. The velocity of the wave on the transmission line multiplied by the velocity of light in a vacuum

 c. The ratio of the characteristic impedance of the line to the terminating impedance

 d. The velocity of the wave on the transmission line divided by the velocity of light in a vacuum

509. A transmission line consisting of two conductors that have equal resistance per unit length.

 a. Unbalance line

 b. Open-wire line

 c. Balanced line

 d. Coaxial line

510. Which if the following is not a common transmission line impedance?

 a. 50 Ω

 b. 75 Ω

 c. 120 Ω

 d. 300 Ω

511. For a maximum absorption of power at the antenna, the relationship between the characteristic impedance of the line Zo and the load impedance Zl should be

 a. Zo = ZL

 b. Zo > ZL

 c. Zo < ZL

 d. Zo = 0

512. Which of the following determines the characteristics of a transmission line?  a. Inductance

 b. Capacitance

 c. Physical dimensions

 d. Length

513. In the study of transmission cable, twin lead is also referred to as a ______.

 a. Twisted pair

 b. Double cable

 c. Ribbon cable

 d. Open pair

514. A 50 Ω coax is connected to a 73 Ω the SWR is

 a. 0.685

 b. 1

 c. 1.46

 d. 2.92

515. A ratio expressing the percentage of incident voltage reflected on a transmission line is known as the

 a. Velocity factor

 b. Standing-wave ratio

 c. Reflection coefficient

 d. Line efficient

516. Three feet is one wavelength at a frequency of

 a. 100 MHz

 b. 164 MHz

 c. 300 MHz

 d. 328 MHz 517. An open quarter-wave line at the operating frequency acts like a(n)

 a. Series resonant circuit

 b. Parallel resonant circuit

 c. Capacitor

 d. Inductor

518. A shorted half-wave line at the operating frequency acts like a(n)

 a. Capacitor

 b. Inductor

 c. Series resonant circuit

 d. Parallel resonant circuit

519. At UHF and microwave frequencies, transmission lines are commonly used as

 a. Antenna

 b. Coupler

 c. Resonant circuit

 d. Transformer

520. The transmission medium subjects the transmitted signal to be

 a. Modulated

 b. Amplified

 c. Attenuated

 d. Boosted

521. Transmission line is a two-wire cable that connects the transmitter to the antenna or the antenna to the receiver. The purpose of the transmission line is to

 a. Amplify the RF signal

 b. Modulate the signal

 c. Carry the RF energy for the desired distance  d. All of the above

522. These conductors are uniformly spaced by insulators. They have low losses at low medium frequencies and are economical to construct and maintained

 a. Coaxial cables

 b. Open-wire transmission lines

 c. Optical cables

 d. Waveguides

523. To prevent radiation losses and interference from external sources, the inner conductor of this transmission line is completely enclosed with a metal sheath or braid

 a. Coaxial cable

 b. Open-wire transmission lines

 c. Optical cables

 d. Waveguides

524. The term “balanced line” means that

 a. Both conductors carry currents that flow in opposite directions

 b. Conductors present equal capacitance to ground

 c. One conductor is connected to ground

 d. Both A and B

525. The characteristic impedance of a transmission line is determined by:

 a. Its operating frequency

 b. Its length

 c. Its physical size and arrangement

 d. The signal applied at the input terminal

526. The disturbance parameters of the transmission line are: the series resistance; the series inductance; the shunt capacitance and the shunt conductance. What parameter was determined due to dielectric losses?

 a. Series resistance  b. Series inductance

 c. Shunt capacitance

 d. Shunt conductance

527. Shunt capacitance was determined due to:

 a. Conductors were closed to each other

 b. The length and diameter of the conductors

 c. Dielectric loses

 d. Flux linkages

528. Series resistances was determined due to:

 a. Conductors were closed to each other

 b. The length and diameter of the conductors

 c. Dielectric losses

 d. Flux linkages

529. At radio frequencies was determined due to:

 a. Characteristic

 b. Inductive reactance is much larger than the shunt conductance

 c. Capacitive reactance is much larger than the shunt conductance

 d. Both b and c

530. Determine the characteristic impedance of a transmission line which has a capacitance of 30 pF/m and an inductance of 75 nH/m

 a. 5 Ω

 b. 50 Ω

 c. 500 Ω

 d. 5 K Ω

531. If a charge in the dielectric material decreases the capacitance, the characteristic impedance is  a. Kept constant

 b. Decreased

 c. Increased

 d. Halved

501. A short circuited stub at some 519. Resonant circuit specific distance from the load 520. Attenuated 502. Depends on the dielectric constant 521. Carry the RF energy for the desired of the material used distance 503. 75 ohms 522. Open-wire transmission lines 504. Below 2 GHz 523. Coaxial cable 505. Velocity factor 524. Both A and B 506. Narrow bandwidth 525. Its physical size and arrangement 507. Balun 526. Shunt conductance 508. The velocity of the wave on the 527. Conductors were closed to each transmission line multiplied by the other velocity of light in a vacuum 528. The length and diameter of the 509. Balanced line conductors 510. 120 Ω 529. Both b and c 511. Zo = ZL 530. 50 Ω 512. Physical dimensions 531. Increased 513. Ribbon cable 514. 1.46 515. Reflection coefficient Read 516. 328 MHz more: http://www.pinoybix.com/2015/01/answers- 517. Series resonant circuit in-transmission-fundamentals- 518. Series resonant circuit part11.html#ixzz3OxqTjjbP