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Home , Electromagnetic spectrum, Violet (color), Visible spectrum

MCAS Student Practice Questions UNIT 6 – Electromagnetic Answers with Explanations

STANDARD 6.1 6.1. Recognize that electromagnetic are transverse waves and travel at the speed of through a vacuum.

8 BASIC CONCEPT: All Electromagnetic Waves travel at 3.0 x 10 m/s in a vacuum or air.

11-21 6.1 8-9 6.1X-ray waves and waves are both The table below lists the in four different electromagnetic waves. Which of the following situations. describes another property x-ray waves and infrared Situation Speed of Light (m/s) waves share? A 8 3.0 x 10 A. Both waves are longitudinal. B 2.2 x 108 B. Both waves have the same . C 1.9 x 108 C. Both waves have the same D 1.7 x 108 .

D. Both waves travel at the same speed In which situation is light traveling through a vacuum? in a vacuum. A. Light travels at 3.0 x 108 in a vacuum. D. Light travels at 3.0 x 108 in a vacuum.

9-30 6.1 In an electromagnetic , an 10-4 6.1 exists perpendicular to a , and both fields are Which of the following properties is the same for all perpendicular to the direction of travel of the wave. These electromagnetic waves in a vacuum? characteristics indicate that an electromagnetic wave is A. amplitude which of the following wave types? A. gravitational B. frequency B. longitudinal C. speed C. mechanical D. wavelength

D. transverse

C. The speed is 3.0 x 108 for all EM waves. D. Perpendicular movement in a wave means it is a transverse. 7-38 6.1 Which of the following waves can travel at a speed of 3 × 108 m/s? A. B. seismic waves

C. ultrasonic waves D. water waves The speed is 3.0 x 108 for all EM waves.

15-36 STD 6.1 Which of the following statements 15-28 STD 6.1 When astronauts landed on the Moon, describes electromagnetic waves? helped them communicate with people on A. They have mass. B. They are transverse waves. Earth. It took 1.3 s for a to travel from the Moon to C. They require a medium to propagate. Earth. Which of the following is the best estimate of the D. They travel at varying speeds through a vacuum. distance between Earth and the Moon? A. 115,000,000 m B. 231,000,000 m C. 390,000,000 m D. 780,000,000 m

D = R T, R = 3 x 10 8 m/s T = 1.3 s

D = 3 x 10 8 m/s x 1.3 s

Notice that 3 x 1.3 = 3.9, there is only one answer that has 39 in it. That is the answer.

STANDARD 6.2 6.2. Describe the electromagnetic in terms of frequency and wavelength and identify the location of radio waves, microwaves, infrared radiation, visible light (, , , , , , and ), rays, x-rays, and gamma rays on the spectrum.

11-28 6.2 The figure below shows regions of the .

Which of the following devices is designed to produce electromagnetic radiation with the longest wavelength in order to operate?

A. Light bulb B. oven C. x-ray microscope D. FM radio .

Large are at the Left end of the Spectrum. 10-13 6.2 8-1 6.2 Which of the following properties determines a Radio waves, visible light, and x-rays are examples of in the visible light region of the electromagnetic electromagnetic waves that always differ from each spectrum? other in A. acceleration A. amplitude. B. amplitude B. intensity. C. frequency C. temperature. D. speed D. wavelength.

EM waves differ in Wavelength and Frequency.

9-6 6.2 Which of the following statements best 9-21 6.2 describes the of light as seen by the Which of the following statements best describes an ? electromagnetic wave with a long wavelength? A. The lowest frequency appears red, and A. It has a and can travel in the highest frequency appears violet. a vacuum. B. The lowest frequency appears red, and the highest B. It has a and can travel in a frequency appears yellow. vacuum. C. The lowest frequency appears green, and the highest C. It has a low frequency and can only travel in a frequency appears violet. medium. D. The lowest frequency appears green, and the highest D. It has a high frequency and can only travel in a frequency appears yellow. medium.

RED = Low Frequency (High Wavelength) All EM waves can travel in a vacuum. Long VIOLET = High Frequency (Low Wavelength) Wavelength = Low Frequency

8-13 6.2 7-31 4.2 Suppose a scientist detects an electromagnetic wave Which of the following waves travels fastest? with a frequency higher than those of gamma rays. A. water waves in oceans The scientist labels this wave a Z-ray. Which of the following would always be true of a Z-ray? B. seismic waves in rocks A. A Z-ray would have a lesser C. sound waves from a violin string amplitude than gamma rays. D. electromagnetic waves from the B. A Z-ray would have a greater amplitude than gamma rays.

C. A Z-ray would have a shorter wavelength than gamma rays. EM (including Light) are the fastest waves.

D. A Z-ray would have a longer

wavelength than gamma rays.

Higher Frequency means a shorter wavelength.

7-29 6.2 & 4.1 Which of the following graphs best represents the relationship of the frequency of an electromagnetic wave to its wavelength?

D. As wavelength becomes longer the frequency becomes shorter.

7-35 4.2 7-42 6.2 Which of the following can carry light waves but Ultraviolet light has a shorter wavelength than not sound waves? visible light. Which of the following is another A. air way ultraviolet light can be compared to visible light? B. steel A. Ultraviolet light has a lower C. water frequency than visible light. D. vacuum B. Ultraviolet light has a higher frequency than visible light. C. Ultraviolet light travels faster Remember that is a vacuum and light from the than visible light. sun makes it to Earth. D. Ultraviolet light travels slower than visible light.

Wavelength and Frequency are inversely related.

When one is high the other is low.

8-13 6.2 Suppose a scientist detects an electromagnetic 7-31 4.2 Which of the following waves travels fastest? wave with a frequency higher than those of gamma rays. A. water waves in oceans The scientist labels this wave a Z-ray. Which of the B. seismic waves in rocks following would always be true of a Z-ray? C. sound waves from a violin string A. A Z-ray would have a lesser amplitude than a . D. electromagnetic waves from the Sun B. A Z-ray would have a greater amplitude than a gamma ray. C. A Z-ray would have a shorter wavelength than gamma rays. The speed of light is the fastest speed that anything can go D. A Z-ray would have a longer wavelength than gamma rays.

OPEN RESPONSE 10-32 Standard: 6.2 - Describe the electromagnetic spectrum in terms of frequency and wavelength and identify the locations of radio waves, microwaves, infrared radiation, visible light (red, orange, yellow, green, blue, indigo, and violet), ultraviolet rays, x-rays, and gamma rays on the spectrum.

When some elements are put into a flame, they emit colored light. Yellow light is emitted from one element and violet light is emitted from another element.

a. Describe the differences between yellow light and violet light in terms of frequency and wavelength. The diagram below represents violet light.

Remember the Order of the Spectrum : Starting with High Wavelength R O Y G B I V ending with Short Wavelength. Use this information to answer the question:

Yellow light has a shorter wavelength than Violet light. Yellow light has a higher frequency than violet light.

b. Copy the diagram of violet light into your Student Answer Booklet. Below your diagram, draw and label a representation of yellow light that illustrates how its frequency and wavelength are different from that of violet light.

Yellow has longer wavelength and lower frequency

c. Yellow light and violet light are both in the visible range of the electromagnetic spectrum. Identify two other similarities between yellow light and violet light. Yellow light and Violet light both travel at the speed of light, they also travel through a vacuum.