Question 1

A radar pulse sent out to an airplane at a distance of 20.0 km will return as an echo to the source in what time interval? (c = 3.00 * 10⁸ m/s) A) 33.3 *10^-⁶ s B) 133 *10^-⁶ s C) 66.7 * 10^-⁶ s D) 0.0333 *10^-⁶ s

Accepted Answer

The answer of A radar pulse sent out to an...

Question 2

Which condition of motion must be met with regard to a charged particle if it is in the process of emitting electromagnetic radiation?
A) accelerates
B) moves at the speed of light
C) moves at constant velocity
D) moves parallel to a uniform magnetic field

Accepted Answer

A charged particle emits electromagnetic radiation when it accelerates. This is because acceleration causes a change in the electric and magnetic fields associated with the particle, leading to the emission of radiation.

Question 3

Temperature variation of different parts of a person's body can be detected by analyzing the emission pattern of which type of electromagnetic radiation?
A) microwave
B) infrared
C) x-rays
D) ultraviolet

Accepted Answer

Infrared radiation is emitted by all objects based on their temperature, and it is commonly used in thermal imaging to detect temperature variations in the human body.

Question 4

What value of inductance should be used in a series circuit with a capacitor of 9.0 *10^-⁴ $\mu$F when designed to radiate a wavelength of 70 m? (c = 3.00 * 10⁸ m/s) A) 3.8* 10^-⁴ mH B) 1.9 *10^-⁴ mH C) 3.8 mH D) 1.5 *10 ^- ³ mH

Accepted Answer

The answer of What value of inductance should be used...

Question 5

An object that is giving off only infrared electromagnetic waves is giving off heat through:
A) radiation.
B) conduction.
C) convection.
D) visible light.

Accepted Answer

Radiation is the transfer of heat through electromagnetic waves, including infrared waves, without the need for a medium.

Question 6

Of the various types of electromagnetic radiation, the shortest wavelengths are the most penetrating through all forms of matter. Which of the following is it?
A) ultraviolet
B) gamma
C) infrared
D) visible light

Accepted Answer

Gamma rays have the shortest wavelengths in the electromagnetic spectrum, which gives them the highest energy and the greatest penetrating power through matter.

Question 7

The electromagnetic radiation that causes tanning:
A) rarely passes through glass windows.
B) is absorbed by ozone.
C) can produce cancer.
D) is all of the above.

Accepted Answer

The electromagnetic radiation that causes tanning is ultraviolet radiation, which is a type of ionizing radiation. Ultraviolet radiation can produce cancer, and it is absorbed by ozone. Ultraviolet radiation can also pass through glass windows, but it is not as effective at doing so as other types of electromagnetic radiation, such as visible light.

Question 8

The human eye is sensitive to light with wavelength up to 750 nm. What is the frequency of radiation at this wavelength? (1 nm = 10^-⁹ m and c = 3.00 * 10⁸ m/s) A) 8.5 * 10⁸ Hz B) 1.8 * 10⁸ Hz C) 4.0 *10¹⁴ Hz D) 7.7*10¹⁴ Hz

Accepted Answer

The answer of The human eye is sensitive to light...

Question 9

A beam of polarized light of intensity I₀ passes through a sheet of ideal polarizing material. The polarization axis of the beam and the transmission axis of the sheet differ by 45°. What is the intensity of the emerging light? A) 0.25I₀ B) 0.87I₀ C) 0.50I₀ D) 0.75I₀

Accepted Answer

When a beam of polarized light passes through a sheet of ideal polarizing material whose polarization axis is at 45 degrees to the incident polarization axis, the intensity of light that emerges is half of the incident intensity. Thus, the intensity of the emerging light is 0.5 times I₀, which is equal to 0.50I₀. Therefore, the correct answer is choice C.

Question 10

An ultraviolet light wave has a wavelength of 300 nm and speed of 1.8 * 10⁸m/s through a transparent medium. What is the frequency of this wave in the medium? (1 nm = 10^-⁹ m and c = 3.00 * 10⁸ m/s) A) 7.0 * 10¹⁴ Hz B) 6.0 * 10¹⁴ Hz C) 6.3 * 10²Hz D) 10 * 10¹⁴Hz

Accepted Answer

The frequency (f) can be calculated using the formula f = v/λ, where v is the speed of the wave in the medium and λ is the wavelength. Here, v = 1.8 x 10^8 m/s and λ = 300 nm = 300 x 10^-9 m. Thus, f = (1.8 x 10^8 m/s) / (300 x 10^-9 m) = 6.0 x 10^14 Hz.

Question 11

When an electrical switch is closed or opened in the vicinity of an operating AM radio, a burst of static can be heard. Which of the following, involving the throwing of the switch, would likely be the cause for this static?
A) The sound from the switching is the source of waves.
B) Unnoticed lightning hits nearby every time the switch is thrown.
C) Static happens without any cause.
D) Electrons are accelerated during the switching process.

Accepted Answer

When the switch is thrown, electrons are accelerated, causing electromagnetic interference that can be picked up as static by the AM radio.

Question 12

Find the frequency of X-rays of wavelength 2 *10^-¹¹m. (c = 3*10⁸ m/s) A) 3 * 10⁸ Hz B) 1.5 * 10¹⁹Hz C) 3 * 10¹⁸ Hz D) 6 *10⁹ Hz

Accepted Answer

The frequency (f) is calculated using the formula f = c/λ, where c is the speed of light (3 x 10^8 m/s) and λ is the wavelength (2 x 10^-11 m). Substituting the values gives f = (3 x 10^8) / (2 x 10^-11) = 1.5 x 10^19 Hz.

Question 13

In order to keep its food hot, a restaurant will place it under which type of lamp?
A) ultraviolet
B) visible light
C) infrared
D) X-ray

Accepted Answer

Infrared lamps are used to keep food warm because they emit heat that can be absorbed by the food, maintaining its temperature.

Question 14

As an electromagnetic wave travels through free space, its speed can be increased by:
A) increasing its frequency.
B) increasing its energy only.
C) increasing both its energy and momentum.
D) None of the above will increase its speed.

Accepted Answer

The speed of an electromagnetic wave is mostly determined by the properties of the medium it is passing through, such as the electric permittivity and magnetic permeability. In free space, the speed of light, which is an electromagnetic wave, is constant and cannot be altered by changing its frequency or energy.

Question 15

Polaroid sunglasses help when skiing on snow on a sunny day by reducing the sunlight from the snow. This light from the snow has been polarized by:
A) optical activity.
B) selective absorption.
C) reflection.
D) double refraction.

Accepted Answer

When sunlight reflects off surfaces like snow, it becomes polarized, meaning the light waves vibrate in a particular direction. Polaroid sunglasses are designed to block this polarized light, reducing glare and improving visibility.

Question 16

A radio wave signal, which transmits at a frequency of 10.4 MHz, has what wavelength? (c = 3.00*10⁸ m/s) A) 28.8 m B) 2.4 *10^-² m C) 4.17 m D) 41.7 m

Accepted Answer

The answer of A radio wave signal, which transmits at...

Question 17

When the Sun is located near one of the horizons, an observer looking at the sky directly overhead will view partially polarized light. This effect is due to which of the following processes?
A) double refraction
B) optical activity
C) selective absorption
D) reflection

Accepted Answer

The polarization of light when the Sun is near the horizon is primarily due to scattering, which is a form of reflection, as sunlight interacts with atmospheric particles.

Question 18

Glass panes are opaque to a certain type of radiation, which can cause sunburn. What type of radiation is it? This radiation is important in ozone layer reactions.
A) gamma
B) ultraviolet
C) X-ray
D) microwave

Accepted Answer

Ultraviolet (UV) radiation is the type of radiation that glass panes are opaque to, and it is also responsible for causing sunburn. UV radiation plays a significant role in reactions involving the ozone layer.

Question 19

What is the wavelength of 200 MHz television EM waves? (c = 3 * 10⁸ m/s) A) 9 km B) 10 m C) 1.5 m D) 3 m

Accepted Answer

The wavelength of an electromagnetic wave is given by the formula:λ = c / fwhere:λ is the wavelength in metersc is the speed of light in meters per secondf is the frequency in hertzIn this case, the frequency is 200 MHz, which is equal to 200 x 10^6 Hz. The speed of light is 3 x 10^8 m/s. Substituting these values into the formula, we get:λ = 3 x 10^8 m/s / 200 x 10^6 Hz = 1.5 mTherefore, the wavelength of the television EM waves is 1.5 m.

Question 20

Unpolarized light of intensity I₀ passes through two sheets of ideal polarizing material. If the transmitted intensity is 0.375I₀, what is the angle between the polarizers? A) 22.5° B) 60° C) 30° D) 45°

Accepted Answer

When unpolarized light passes through a polarizing material, its intensity reduces to half. Thus, if the intensity of the unpolarized light is IS1U1B10S1U1B0 and it passes through one polarizing material, the intensity of the transmitted light is IS1U1B20S1U1B0/2 = IS1U1B10S1U1B0/2.
When this partially polarized light passes through another polarizing material, its intensity reduces further to (1/2) * (IS1U1B10S1U1B0/2) = IS1U1B10S1U1B0/4.
Given that the transmitted intensity is 0.375IS1U1B10S1U1B0, we can write:
IS1U1B10S1U1B0/4 = 0.375IS1U1B10S1U1B0
Therefore, IS1U1B10S1U1B0 cancels out and we get:
1/4 = 0.375
Multiplying both sides by 4, we get:
1 = 1.5
This is a contradiction, which means our assumption that the light passed through two polarizing materials is incorrect. Thus, the angle between the polarizers must be 0 degrees or 90 degrees. When the angle is 0 degrees, all the light can pass through both polarizers, so the transmitted intensity should be IS1U1B10S1U1B0/2 * 2 = IS1U1B10S1U1B0, which is not what we have. Thus, the angle must be 30 degrees (which is cos^2(30) = 0.375).

Quiz 23: Electromagnetic Waves

A radar pulse sent out to an airplane at a distance of 20.0 km will return as an echo to the source in what time interval? (c = 3.00 * 10⁸ m/s)

Which condition of motion must be met with regard to a charged particle if it is in the process of emitting electromagnetic radiation?

Temperature variation of different parts of a person's body can be detected by analyzing the emission pattern of which type of electromagnetic radiation?

What value of inductance should be used in a series circuit with a capacitor of 9.0 10^-⁴ $\mu$ F when designed to radiate a wavelength of 70 m? (c = 3.00 10⁸ m/s)

An object that is giving off only infrared electromagnetic waves is giving off heat through:

Of the various types of electromagnetic radiation, the shortest wavelengths are the most penetrating through all forms of matter. Which of the following is it?

The electromagnetic radiation that causes tanning:

The human eye is sensitive to light with wavelength up to 750 nm. What is the frequency of radiation at this wavelength? (1 nm = 10^-⁹ m and c = 3.00 * 10⁸ m/s)

A beam of polarized light of intensity I₀ passes through a sheet of ideal polarizing material. The polarization axis of the beam and the transmission axis of the sheet differ by 45°. What is the intensity of the emerging light?

An ultraviolet light wave has a wavelength of 300 nm and speed of 1.8 * 10⁸m/s through a transparent medium. What is the frequency of this wave in the medium? (1 nm = 10^-⁹ m and c = 3.00 * 10⁸ m/s)

When an electrical switch is closed or opened in the vicinity of an operating AM radio, a burst of static can be heard. Which of the following, involving the throwing of the switch, would likely be the cause for this static?

Find the frequency of X-rays of wavelength 2 10^-¹¹m. (c = 310⁸ m/s)

In order to keep its food hot, a restaurant will place it under which type of lamp?

As an electromagnetic wave travels through free space, its speed can be increased by:

Polaroid sunglasses help when skiing on snow on a sunny day by reducing the sunlight from the snow. This light from the snow has been polarized by:

A radio wave signal, which transmits at a frequency of 10.4 MHz, has what wavelength? (c = 3.00*10⁸ m/s)

When the Sun is located near one of the horizons, an observer looking at the sky directly overhead will view partially polarized light. This effect is due to which of the following processes?

Glass panes are opaque to a certain type of radiation, which can cause sunburn. What type of radiation is it? This radiation is important in ozone layer reactions.

What is the wavelength of 200 MHz television EM waves? (c = 3 * 10⁸ m/s)

Unpolarized light of intensity I₀ passes through two sheets of ideal polarizing material. If the transmitted intensity is 0.375I₀, what is the angle between the polarizers?