Question 1

Complete the following sentence: When electrons from a heated filament accelerate through vacuum toward a positive plate,

Accepted Answer

When accelerated electrons strike a positive plate, they release their energy in the form of electromagnetic waves, also known as light. This phenomenon is the basis for the production of light in incandescent bulbs. Therefore, electromagnetic waves will be produced.

Question 2

When a radio telescope observes a region of space between two stars, it detects electromagnetic radiation that has a wavelength of 0.21 m. This radiation was emitted by hydrogen atoms in the gas and dust located in that region. What is the frequency of this radiation?

Accepted Answer

The frequency of electromagnetic radiation can be calculated using the formula: frequency (f) = speed of light (c) / wavelength (λ). The speed of light is approximately 3.0 × 10^8 m/s. So, f = 3.0 × 10^8 m/s / 0.21 m = 1.428 × 10^9 Hz, which is closest to 1.4 × 10^9 Hz.

Question 3

Which one of the following colors of visible light has the highest frequency?

Accepted Answer

The frequency of visible light is directly proportional to its wavelength. Violet light has the shortest wavelength of all the visible colors, which means it has the highest frequency.

Question 4

Which one of the following will not generate electromagnetic waves or pulses?

Accepted Answer

Electromagnetic waves or pulses are generated by varying electric and magnetic fields. A steady direct current has a constant electric and magnetic field and therefore will not generate electromagnetic waves or pulses.

Question 5

The average distance between the surface of the earth and the surface of the sun is 1.49 × 10¹¹ m. How much time, in minutes, does it take light leaving the surface of the sun to reach the earth?

Accepted Answer

The speed of light is approximately 3 × 108 m/s. To find the time it takes for light to travel from the sun to the earth, we divide the distance by the speed of light:

1.49 × 1011 m ÷ 3 × 108 m/s ≈ 493 seconds ≈ 8.3 minutes

Therefore, the answer is choice C, 8.3 min.

Question 6

A distant space probe is programmed to emit a radio signal toward Earth at regular time intervals. One such pulse arrives on Earth 6.92 s after it is emitted from the probe. What is the approximate distance from the Earth to the probe?

Accepted Answer

The answer of A distant space probe is programmed to...

Question 7

Which one of the following wavelengths is in the infrared range of the electromagnetic spectrum?

Accepted Answer

The wavelength of 20 µm is in the infrared range of the electromagnetic spectrum, which is typically defined as having wavelengths between 700 nm and 1 mm. Choices A, B, C, and D have wavelengths outside of this range.

Question 8

An FM radio station generates radio waves that have a frequency of 101.3 MHz. The frequency of the waves from a competing station have a frequency of 107.1 MHz. What is the difference in wavelength between the waves emitted from the two stations?

Accepted Answer

The answer of An FM radio station generates radio waves...

Question 9

Which one of the following statements concerning electromagnetic waves is false?

Accepted Answer

X-rays have shorter wavelengths and higher frequencies than radio waves.

Question 10

Which one of the following scientists did not attempt to measure the speed of light?

Accepted Answer

Maxwell did not attempt to measure the speed of light; he developed the theory of electromagnetism, which predicted the speed of light.

Question 11

Note the different types of electromagnetic radiation:  Which list correctly ranks the electromagnetic waves in order of increasing frequency?

Accepted Answer

The electromagnetic waves are arranged in the following order: 
1. Radio waves (2)
2. Microwaves (5)
3. Infrared radiation (4)
4. Visible light (6)
5. Ultraviolet radiation (1)
6. X-rays (3)

Therefore, the correct order of increasing frequency is 2, 5, 4, 6, 1, 3, and the best choice is C.

Question 12

Complete the following sentence: The various colors of visible light differ in

Accepted Answer

The colors of visible light differ in both frequency and wavelength. Different colors have different wavelengths and frequencies, which can be observed in phenomena such as refraction and diffraction.

Question 13

Which one of the following types of wave is fundamentally different than the other four?

Accepted Answer

Sound waves are fundamentally different from the other options because they require a medium to travel through, while the other options can travel through a vacuum (i.e. empty space). Radio waves, gamma rays, ultraviolet radiation, and visible light are all forms of electromagnetic radiation, whereas sound waves are a type of mechanical wave.

Question 14

The electric field E of an electromagnetic wave traveling the positive x direction is illustrated in the figure. This is the wave of the radiation field of an antenna. What are the direction and the phase relative to the electric field of the magnetic field at a point where the electric field is in the negative y direction? Note: The wave is shown in a region of space that is a large distance from its source.

Accepted Answer

The answer of The electric field E of an electromagnetic...

Question 15

A radio wave sent from the surface of the earth reflects from the surface of the moon and returns to the earth. The elapsed time between the generation of the wave and the detection of the reflected wave is 2.6444 s. Determine the distance from the surface of the earth to the surface of the moon. Note: The speed of light is 2.9979 × 10⁸ m/s.

Accepted Answer

The distance traveled by the radio wave is twice the distance from the earth to the moon. 
Let x be the distance from the surface of the earth to the surface of the moon.
The total distance traveled is 2x. 
Using the formula: distance = speed x time, we have 
2x = (2)(2.9979 × 10^8 m/s)(2.6444 s) 
2x = 15.8897 × 10^8 m 
x = 7.9449 × 10^8 m 
The distance from the surface of the earth to the surface of the moon is half of x, which gives 
x/2 = 3.9638 × 10^8 m 
Therefore, the answer is C.

Question 16

Which one of the following statements concerning the wavelength of an electromagnetic wave in a vacuum is true?

Accepted Answer

The wavelength of an electromagnetic wave is inversely proportional to its frequency, as described by the equation $ \lambda = \frac{c}{f} $, where $ \lambda $ is the wavelength, $ c $ is the speed of light, and $ f $ is the frequency.

Question 17

Which one of the following statements concerning electromagnetic waves is false?

Accepted Answer

Electromagnetic waves are actually transverse waves, not longitudinal.

Question 18

What is the correct order, beginning with shortest wavelength and extending to the longest wavelength, of the following colors in the visible light spectrum: blue, green, red, violet, and yellow?

Accepted Answer

The correct order, beginning with shortest wavelength and extending to the longest wavelength, of the following colors in the visible light spectrum is: violet, blue, green, yellow, and red. Therefore, option D is the best choice.

Question 19

In 1980, a television station began broadcasting on channel 32 at a frequency of 582 MHz. The circuit contains an inductor with an inductance L = 4.15 × 10^-⁴ H and a variable-capacitance C. Determine the value of C that allows this television station to be tuned in.

Accepted Answer

The answer of In 1980, a television station began broadcasting...

Question 20

A cellular telephone transmits electromagnetic waves at a frequency of 835 MHz. What is the wavelength of these waves?

Accepted Answer

The wavelength (λ) can be calculated using the formula λ = c/f, where c is the speed of light (approximately 3 x 10^8 m/s) and f is the frequency. For 835 MHz (which is 835 x 10^6 Hz), the wavelength is approximately 0.359 m.

Quiz 24: Electromagnetic Waves

Complete the following sentence: When electrons from a heated filament accelerate through vacuum toward a positive plate,

When a radio telescope observes a region of space between two stars, it detects electromagnetic radiation that has a wavelength of 0.21 m. This radiation was emitted by hydrogen atoms in the gas and dust located in that region. What is the frequency of this radiation?

Which one of the following colors of visible light has the highest frequency?

Which one of the following will not generate electromagnetic waves or pulses?

The average distance between the surface of the earth and the surface of the sun is 1.49 × 1011 m. How much time, in minutes, does it take light leaving the surface of the sun to reach the earth?

A distant space probe is programmed to emit a radio signal toward Earth at regular time intervals. One such pulse arrives on Earth 6.92 s after it is emitted from the probe. What is the approximate distance from the Earth to the probe?

Which one of the following wavelengths is in the infrared range of the electromagnetic spectrum?

An FM radio station generates radio waves that have a frequency of 101.3 MHz. The frequency of the waves from a competing station have a frequency of 107.1 MHz. What is the difference in wavelength between the waves emitted from the two stations?

Which one of the following statements concerning electromagnetic waves is false?

Which one of the following scientists did not attempt to measure the speed of light?

Note the different types of electromagnetic radiation: Which list correctly ranks the electromagnetic waves in order of increasing frequency?

Complete the following sentence: The various colors of visible light differ in

Which one of the following types of wave is fundamentally different than the other four?

Which one of the following statements concerning the wavelength of an electromagnetic wave in a vacuum is true?

Which one of the following statements concerning electromagnetic waves is false?

What is the correct order, beginning with shortest wavelength and extending to the longest wavelength, of the following colors in the visible light spectrum: blue, green, red, violet, and yellow?

In 1980, a television station began broadcasting on channel 32 at a frequency of 582 MHz. The circuit contains an inductor with an inductance L = 4.15 × 10-4 H and a variable-capacitance C. Determine the value of C that allows this television station to be tuned in.

A cellular telephone transmits electromagnetic waves at a frequency of 835 MHz. What is the wavelength of these waves?

The average distance between the surface of the earth and the surface of the sun is 1.49 × 10¹¹ m. How much time, in minutes, does it take light leaving the surface of the sun to reach the earth?

In 1980, a television station began broadcasting on channel 32 at a frequency of 582 MHz. The circuit contains an inductor with an inductance L = 4.15 × 10^-⁴ H and a variable-capacitance C. Determine the value of C that allows this television station to be tuned in.