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.