Question 1

In the 19th century, it became clear that magnetism was not a separate force, but was always produced by the action of
A) electric charges that were in motion
B) the gravitational pull of the Earth
C) the strong nuclear force acting on electrons
D) light moving through a vacuum
E) something possessed by all movie stars

Accepted Answer

In the 19th century, it was discovered that magnetism was always produced by the motion of electric charges. This became known as electromagnetism, which explained the relationship between electric and magnetic fields.

Question 2

This chapter discusses that light sometimes acts like a photon. What is a photon?
A) a charged particle in the nucleus of every atom
B) a kind of magnetic substance found in reflective minerals
C) a self-contained "packet" of electro-magnetic energy
D) a kind of sound that is too high frequency for the human ear to hear
E) you can't fool me. Einstein showed that photons were a mistake - they don't exist.

Accepted Answer

A photon is a self-contained "packet" of electro-magnetic energy, also known as a quantum of light. It behaves both like a particle and a wave, and carries a specific amount of energy proportional to its frequency.

Question 3

The scientist who worked out the mathematics of the connections between electricity, magnetism, and light in the 19th century was:
A) Albert Einstein
B) James Clerk Maxwell
C) Isaac Newton
D) Wilhelm Wien
E) Ludwig Boltzmann

Accepted Answer

James Clerk Maxwell is credited with formulating the mathematical equations that describe the connections between electricity, magnetism, and light, known as Maxwell's equations.

Question 4

A fashion designer decides to bring out a new line of clothing which reflects the longest wavelength of visible light. What color will these articles of clothing be to the human eye?
A) yellow-green
B) blue
C) violet
D) red
E) black

Accepted Answer

The answer of A fashion designer decides to bring out...

Question 5

Which of the following has the longest wavelength?
A) radio waves
B) visible light waves
C) ultraviolet waves
D) x-rays
E) you can't fool me, all these have the same wavelength

Accepted Answer

The answer of Which of the following has the longest...

Question 6

Not all wavelengths of electromagnetic radiation can penetrate the Earth's atmosphere. Of the following types of waves that come from space, which one are you likely to be able to detect most easily from our planet's surface:
A) x-rays
B) gamma rays
C) infrared waves
D) ultraviolet waves
E) radio waves of the wavelength that carry FM broadcasts

Accepted Answer

Radio waves of the wavelength that carry FM broadcasts have longer wavelengths and lower frequencies compared to x-rays and gamma rays, allowing them to penetrate the Earth's atmosphere and be detected easily from the surface. Infrared waves and ultraviolet waves can also reach the surface, but may be absorbed by certain atmospheric gases.

Question 7

Which of the following statements about the nucleus of a typical atom (such as a carbon atom in your little finger) is FALSE:
A) the nucleus has an overall positive charge
B) the nucleus takes up a very small amount of space compared to the entire atom
C) the nucleus contains both protons and neutrons
D) the nucleus repels the electrons which move around it
E) the nucleus contains most of the mass of the atom

Accepted Answer

The statement "the nucleus repels the electrons which move around it" is false. In fact, the opposite is true - the positively charged nucleus attracts the negatively charged electrons and holds them in orbit around it.

Question 8

Consider a radio wave from the transmitter of your favorite radio station, which has just reached the antenna of the radio in your room. Which of the following statements about this radio wave is CORRECT?
A) it has a frequency very close to the highest possible frequency for electromagnetic waves
B) it traveled between the transmitter and your radio's antenna at the speed of sound
C) its wavelength is much longer than the wavelength of the light you see reflected from the page of this exam
D) the wave was originally produced by electrons that were not moving (at rest) inside the transmitter
E) the reason that it could reach your radio is because all of space is filled with a medium called the aether in which electromagnetic waves can vibrate

Accepted Answer

The answer of Consider a radio wave from the transmitter...

Question 9

The fastest speed in the universe is:
A) the speed of sound
B) the speed of light
C) the speed of electron oscillations
D) the speed with which Mercury orbits the Sun
E) the speed with which weekends seem to pass

Accepted Answer

The answer of The fastest speed in the universe is:
A)...

Question 10

Which of the following statements about photons is FALSE?
A) photons always travel at the speed of light
B) photons each carry a specific amount of energy
C) a photon of visible light cannot pass through the atmosphere of the Earth, and thus cannot be seen at the Earth's surface
D) high energy photons have a high frequency (when thought of as waves)
E) a gamma-ray photon carries more energy than a visible light photon

Accepted Answer

This statement is false as photons of visible light can pass through the Earth's atmosphere and be seen at the surface. This is evident from the fact that we can see the Sun and the blue sky during the day, which are both sources of visible light.

Question 11

How fast do electro-magnetic waves travel?
A) at the speed of sound
B) at the speed of light
C) at the speed of charge
D) at different speeds, depending on the temperature of the atoms that produce them
E) they always have zero speed

Accepted Answer

Electromagnetic waves, including visible light, travel at the speed of light, which is approximately 299,792,458 meters per second in a vacuum.

Question 12

One reason that human eyes evolved to detect visible light is:
A) it is the band of the electromagnetic spectrum with the lowest possible energy and thus easiest to detect
B) it is the only band of the spectrum that can travel through a vacuum
C) it is the band of the spectrum which is the least Doppler shifted coming from the Sun
D) it is a band of the spectrum where the Sun puts out a great deal of energy
E) it is the band of the spectrum where the warm Earth glows the most effectively at night

Accepted Answer

The Sun emits a significant amount of its energy in the visible light spectrum, making it advantageous for human eyes to evolve sensitivity to this range for effective navigation and survival in the environment.

Question 13

Which of the following statements about infrared radiation is TRUE?
A) it is the band of the electromagnetic spectrum where each wave or photon has the greatest energy
B) it was first discovered in 1800 in an experiment using sunlight and thermometers
C) unlike light, infrared can never travel as fast as the speed of light
D) while many stars give off infrared, there is nothing on Earth at the right temperature to emit it
E) it is the radiation responsible for giving sunburns (or in large doses, skin cancer)

Accepted Answer

Infrared radiation was first discovered in 1800 in an experiment using sunlight and thermometers. The other statements are false: A) the band of the electromagnetic spectrum with the greatest energy is gamma rays, not infrared; C) all forms of electromagnetic radiation travel at the speed of light in a vacuum, including infrared; D) many objects on Earth, including humans, emit infrared radiation; E) ultraviolet radiation, not infrared, is responsible for sunburns and skin cancer.

Question 14

The light which allows you to see this very interesting exam is made up of waves. In these waves, the distance between crests is called the:
A) frequency
B) velocity
C) wavelength
D) amplitude
E) you can't fool me; in these waves, the distance between crests is zero

Accepted Answer

The distance between crests in waves is called the wavelength.

Question 15

After a nice dinner around the campfire on a camping trip, you and a friend decide to get away from the fire to observe the stars. As you get farther and farther away, you see the brightness of the fire:
A) increase with distance
B) remain the same
C) decrease as the distance squared
D) change more and more in color (becoming redder)
E) this can't be answered without having more information

Accepted Answer

The brightness of the fire will decrease as the distance squared, according to the inverse square law of light.

Question 16

Most ultraviolet radiation does not penetrate to the Earth's surface. Instead it is absorbed in:
A) the ozone layer
B) the ionosphere
C) the region between the Earth and the Sun
D) stratosphere
E) tanning zone

Accepted Answer

The ozone layer in the Earth's atmosphere absorbs most of the ultraviolet radiation that comes from the sun, preventing it from reaching the Earth's surface. This is why the depletion of the ozone layer is a major concern, as it can lead to increased levels of ultraviolet radiation reaching us on the Earth's surface. The other options listed do not play as significant a role in absorbing ultraviolet radiation.

Question 17

Which of the following statements about electromagnetic radiation is FALSE?
A) it always spreads out at the speed of light
B) it is given off by all objects that are not at a temperature of absolute zero
C) it is typically produced when charged particles oscillate
D) different waves of electromagnetic radiation differ in their wavelength or frequency
E) the radiation consists of tiny charged particles given off by the nuclei of atoms

Accepted Answer

Electromagnetic radiation consists of oscillating electric and magnetic fields, not charged particles given off by the nuclei of atoms.

Question 18

Which of the following has the highest frequency?
A) visible light
B) gamma rays
C) radio waves
D) ultraviolet waves
E) you can't fool me, all these have the same frequency

Accepted Answer

Gamma rays have the highest frequency, which means they have the shortest wavelength and the highest energy.

Question 19

A Hertz is
A) a unit of wavelength
B) a unit of frequency
C) a unit of velocity
D) a unit of loudness
E) a well-known car-rental company

Accepted Answer

The answer of A Hertz is
A) a unit of wavelength
B)...

Question 20

In the future, several students living on board a space station decide to have a race among different types of electromagnetic radiation. Which of the following travels through space the fastest?
A) visible light
B) radio waves
C) infrared
D) x-rays
E) you can't fool me, all of these travel through space at the same speed

Accepted Answer

The answer of In the future, several students living on...

Quiz 5: Radiation and Spectra

In the 19th century, it became clear that magnetism was not a separate force, but was always produced by the action of

This chapter discusses that light sometimes acts like a photon. What is a photon?

The scientist who worked out the mathematics of the connections between electricity, magnetism, and light in the 19th century was:

A fashion designer decides to bring out a new line of clothing which reflects the longest wavelength of visible light. What color will these articles of clothing be to the human eye?

Which of the following has the longest wavelength?

Not all wavelengths of electromagnetic radiation can penetrate the Earth's atmosphere. Of the following types of waves that come from space, which one are you likely to be able to detect most easily from our planet's surface:

Which of the following statements about the nucleus of a typical atom (such as a carbon atom in your little finger) is FALSE:

Consider a radio wave from the transmitter of your favorite radio station, which has just reached the antenna of the radio in your room. Which of the following statements about this radio wave is CORRECT?

The fastest speed in the universe is:

Which of the following statements about photons is FALSE?

How fast do electro-magnetic waves travel?

One reason that human eyes evolved to detect visible light is:

Which of the following statements about infrared radiation is TRUE?

The light which allows you to see this very interesting exam is made up of waves. In these waves, the distance between crests is called the:

After a nice dinner around the campfire on a camping trip, you and a friend decide to get away from the fire to observe the stars. As you get farther and farther away, you see the brightness of the fire:

Most ultraviolet radiation does not penetrate to the Earth's surface. Instead it is absorbed in:

Which of the following statements about electromagnetic radiation is FALSE?

Which of the following has the highest frequency?

A Hertz is

In the future, several students living on board a space station decide to have a race among different types of electromagnetic radiation. Which of the following travels through space the fastest?