Question 1

The strong ultraviolet spectral line emitted by hot hydrogen gas is known as the:

Accepted Answer

A) 21-cm line. 
B) Balmer $\alpha$ line. 
C) Paschen $\alpha$ line. 
D) Lyman $\alpha$ line. 
A) 21-cm line. 
B) Balmer $\alpha$ line. 
C) Paschen $\alpha$ line. 
D) Lyman $\alpha$ line.

Question 2

Earth is about 150,000,000 km from the Sun. How long did it take light to cross Earth's orbit in Rømer's experimental determination of the speed of light?

Accepted Answer

A) about 8 seconds 
B) about 16 seconds 
C) about 8 minutes 
D) about 16 minutes 
A) about 8 seconds 
B) about 16 seconds 
C) about 8 minutes 
D) about 16 minutes

Question 3

How fast and in what direction is a star moving if its spectrum contains a line that shifts from 486.2 nm to 486.3 nm?

Accepted Answer

A) 61.7 km/s away from you 
B) 61.7 km/s toward you 
C) 562 m/s away from you 
D) 562 m/s toward you 
A) 61.7 km/s away from you 
B) 61.7 km/s toward you 
C) 562 m/s away from you 
D) 562 m/s toward you

Question 4

In a radio wave transmitter (such as that used by a radio or TV station), when the frequency of the signals is increased, the:

Accepted Answer

A) wavelength is decreased. 
B) speed of transmission of the waves is increased. 
C) wavelength and speed of transmission both increase. 
D) wavelength remains constant. 
A) wavelength is decreased. 
B) speed of transmission of the waves is increased. 
C) wavelength and speed of transmission both increase. 
D) wavelength remains constant.

Question 5

In terms of wavelengths, gamma rays are:

Accepted Answer

A) shorter than x rays. 
B) between radio and infrared waves. 
C) between x rays and ultraviolet waves. 
D) longer than visible light. 
A) shorter than x rays. 
B) between radio and infrared waves. 
C) between x rays and ultraviolet waves. 
D) longer than visible light.

Question 6

The Doppler shift, describing the way in which the wavelength λ0 of light emitted by a moving object is detected as a different wavelength λ by a stationary observer (with v the object velocity and c the velocity of light), is given by:

Accepted Answer

A) (λ -λ 0)/λ 0 = v/c. 
B) λ.λ0 = vc. 
C) λ - λ0 = (v - c). 
D) λ /λ 0 = v/c. 
A) (λ -λ 0)/λ 0 = v/c. 
B) λ.λ0 = vc. 
C) λ - λ0 = (v - c). 
D) λ /λ 0 = v/c.

Question 7

The first experiment to measure the speed of light accurately was made by the:

Accepted Answer

A) French physicists, Fizeau and Foucault. 
B) Danish astronomer, Rømer. 
C) Italian scientist, Galileo. 
D) German/American physicist, Einstein. 
A) French physicists, Fizeau and Foucault. 
B) Danish astronomer, Rømer. 
C) Italian scientist, Galileo. 
D) German/American physicist, Einstein.

Question 8

An astronomer wants to know whether a particular star has a greater surface temperature than the Sun. What does she need to know about this star to determine its temperature?

Accepted Answer

A) the wavelength at the peak of its spectrum 
B) its distance from the Sun 
C) its size 
D) its age 
A) the wavelength at the peak of its spectrum 
B) its distance from the Sun 
C) its size 
D) its age

Question 9

As of 2018, Voyager 1 is in interstellar space, about 13 billion miles from Earth. How long does it take data transmitted by Voyager 1 to reach the Deep Space Network on Earth?

Accepted Answer

A) about 90 min 
B) about 19 hrs 
C) 3 days 
D) 2 weeks 
A) about 90 min 
B) about 19 hrs 
C) 3 days 
D) 2 weeks

Question 10

If the wavelengths of Hα and Hß, the first two lines of the hydrogen Balmer series, are 656.3 nm and 486.2 nm, respectively, what is the wavelength of Hγ, the third line of the Balmer series?

Accepted Answer

A) 486.2 nm 
B) 1875 nm 
C) 364.6 nm 
D) 434.1 nm 
A) 486.2 nm 
B) 1875 nm 
C) 364.6 nm 
D) 434.1 nm

Question 11

The human eye is most sensitive to light with a wavelength near 550 nm. To what photon energy is the human eye most sensitive?

Accepted Answer

A) 2.49 eV 
B) 3.61 × 10-19 eV 
C) 2.25 eV 
D) 1.83 eV 
A) 2.49 eV 
B) 3.61 × 10-19 eV 
C) 2.25 eV 
D) 1.83 eV

Question 12

The laws governing the energy flux F and wavelength of maximum intensity λmax of emitted radiation from a hot, dense body whose temperature is T are given by (where σ and a are constants):

Accepted Answer

A) F = σT 2, λmax T = a. 
B) F = σT 4, λmax T = a. 
C) F = σT, λmax = a/T 4. 
D) F = σT 4, λmax = aT. 
A) F = σT 2, λmax T = a. 
B) F = σT 4, λmax T = a. 
C) F = σT, λmax = a/T 4. 
D) F = σT 4, λmax = aT.

Question 13

Figure 5-12 in Universe, 11th ed., shows that a blackbody with a temperature of 3000 K emits radiation that peaks at a wavelength much longer than wavelengths in the visible part of the spectrum. This means that:
​   ​

Accepted Answer

A) the object is not visible but might be detected with equipment sensitive to nonvisible radiation. 
B) the object, like all blackbodies, emits no radiation. 
C) the object emits visible radiation, but not as intensely as at longer wavelengths. 
D) no visible radiation is emitted, but visible radiation would be emitted if the temperature of the object were increased. 
A) the object is not visible but might be detected with equipment sensitive to nonvisible radiation. 
B) the object, like all blackbodies, emits no radiation. 
C) the object emits visible radiation, but not as intensely as at longer wavelengths. 
D) no visible radiation is emitted, but visible radiation would be emitted if the temperature of the object were increased.

Question 14

How does the frequency at the red end of the visible spectrum compare with the frequency at the blue-violet end of the visible spectrum?

Accepted Answer

A) It is about twice as big. 
B) It is about half as big. 
C) It is several orders of magnitude smaller. 
D) It is several orders of magnitude larger. 
A) It is about twice as big. 
B) It is about half as big. 
C) It is several orders of magnitude smaller. 
D) It is several orders of magnitude larger.

Question 15

An example of an object that emits no radiation at all is:

Accepted Answer

A) an object with the temperature of outer space. 
B) a blackbody. 
C) an object made of ice. 
D) an object at a temperature of 0 K. 
A) an object with the temperature of outer space. 
B) a blackbody. 
C) an object made of ice. 
D) an object at a temperature of 0 K.

Question 16

What is the energy in electron volts of a photon whose wavelength is the diameter of a typical atom, about 0.1 nm?

Accepted Answer

A) 12.4 keV, or 12,400 eV 
B) 1.24 × 10-7 eV 
C) 1.24 keV, or 1240 eV 
D) 8.061 MeV, or 8,061,000 eV 
A) 12.4 keV, or 12,400 eV 
B) 1.24 × 10-7 eV 
C) 1.24 keV, or 1240 eV 
D) 8.061 MeV, or 8,061,000 eV

Question 17

Choose the correct sequence of electromagnetic radiations, in order of increasing wavelengths.

Accepted Answer

A) radio, IR, visible, UV 
B) UV, visible, radio, IR 
C) UV, visible, IR, radio 
D) visible, UV, IR, radio 
A) radio, IR, visible, UV 
B) UV, visible, radio, IR 
C) UV, visible, IR, radio 
D) visible, UV, IR, radio

Question 18

How does the wavelength at the red end of the visible spectrum compare with the wavelength at the blue-violet end of the visible spectrum?

Accepted Answer

A) It is about twice as big. 
B) It is about half as big. 
C) It is several orders of magnitude smaller. 
D) It is several orders of magnitude larger. 
A) It is about twice as big. 
B) It is about half as big. 
C) It is several orders of magnitude smaller. 
D) It is several orders of magnitude larger.

Question 19

Isotopes of a particular element in the periodic table have which nuclear property in common?

Accepted Answer

A) same number of neutrons but different numbers of protons 
B) same number of neutrons, but different numbers of protons and electrons 
C) same total number of protons and neutrons 
D) same number of protons but different numbers of neutrons 
A) same number of neutrons but different numbers of protons 
B) same number of neutrons, but different numbers of protons and electrons 
C) same total number of protons and neutrons 
D) same number of protons but different numbers of neutrons

Question 20

Wien's law, relating the peak wavelength λmax of light emitted by a dense object to its temperature T, can be represented by:

Accepted Answer

A) λmax = constant × T 4. 
B) λmax T = constant. 
C) λmax = constant/T 2. 
D) λmax/T = constant. 
A) λmax = constant × T 4. 
B) λmax T = constant. 
C) λmax = constant/T 2. 
D) λmax/T = constant.

Exam 5: The Nature of Light

The strong ultraviolet spectral line emitted by hot hydrogen gas is known as the:

Earth is about 150,000,000 km from the Sun. How long did it take light to cross Earth's orbit in Rømer's experimental determination of the speed of light?

How fast and in what direction is a star moving if its spectrum contains a line that shifts from 486.2 nm to 486.3 nm?

In a radio wave transmitter (such as that used by a radio or TV station), when the frequency of the signals is increased, the:

In terms of wavelengths, gamma rays are:

The Doppler shift, describing the way in which the wavelength λ0 of light emitted by a moving object is detected as a different wavelength λ by a stationary observer (with v the object velocity and c the velocity of light), is given by:

The first experiment to measure the speed of light accurately was made by the:

An astronomer wants to know whether a particular star has a greater surface temperature than the Sun. What does she need to know about this star to determine its temperature?

As of 2018, Voyager 1 is in interstellar space, about 13 billion miles from Earth. How long does it take data transmitted by Voyager 1 to reach the Deep Space Network on Earth?

If the wavelengths of Hα and Hß, the first two lines of the hydrogen Balmer series, are 656.3 nm and 486.2 nm, respectively, what is the wavelength of Hγ, the third line of the Balmer series?

The human eye is most sensitive to light with a wavelength near 550 nm. To what photon energy is the human eye most sensitive?

The laws governing the energy flux F and wavelength of maximum intensity λmax of emitted radiation from a hot, dense body whose temperature is T are given by (where σ and a are constants):

Figure 5-12 in Universe, 11th ed., shows that a blackbody with a temperature of 3000 K emits radiation that peaks at a wavelength much longer than wavelengths in the visible part of the spectrum. This means that: ​ ​

How does the frequency at the red end of the visible spectrum compare with the frequency at the blue-violet end of the visible spectrum?

An example of an object that emits no radiation at all is:

What is the energy in electron volts of a photon whose wavelength is the diameter of a typical atom, about 0.1 nm?

Choose the correct sequence of electromagnetic radiations, in order of increasing wavelengths.

How does the wavelength at the red end of the visible spectrum compare with the wavelength at the blue-violet end of the visible spectrum?

Isotopes of a particular element in the periodic table have which nuclear property in common?

Wien's law, relating the peak wavelength λmax of light emitted by a dense object to its temperature T, can be represented by:

Astronomy and the Universe

Knowing the Heavens

Eclipses and the Motion of the Moon

Gravitation and the Waltz of the Planets

Optics and Telescopes

Comparative Planetology I: Our Solar System

Comparative Planetology II: the Origin of Our Solar System

The Living Earth

Our Barren Moon

Mercury, Venus, and Mars: Terrestrial, yet Unique

Jupiter and Saturn: Lords of the Planets

Jupiter and Saturns Satellites of Fire and Ice

Uranus, Neptune, Pluto, and the Kuiper Belt: Remote Worlds

Asteroids, Comets, and Impacts

Our Star, the Sun

The Nature of the Stars

The Birth of Stars

Stellar Evolution: on and After the Main Sequence

Stellar Evolution: The Death of Stars

Stellar Remnants: Neutron Stars and Black Holes

Our Galaxy

Galaxies

Quasars and Active Galaxies

Cosmology: The Origin and Evolution of the Universe

Exploring the Early Universe

The Search for Extraterrestrial Life

Filters

The Doppler shift, describing the way in which the wavelength λ₀ of light emitted by a moving object is detected as a different wavelength λ by a stationary observer (with v the object velocity and c the velocity of light), is given by:

If the wavelengths of H_α and H_ß, the first two lines of the hydrogen Balmer series, are 656.3 nm and 486.2 nm, respectively, what is the wavelength of H_γ, the third line of the Balmer series?

The laws governing the energy flux F and wavelength of maximum intensity λ_max of emitted radiation from a hot, dense body whose temperature is T are given by (where σ and a are constants):

Figure 5-12 in Universe, 11th ed., shows that a blackbody with a temperature of 3000 K emits radiation that peaks at a wavelength much longer than wavelengths in the visible part of the spectrum. This means that:

Wien's law, relating the peak wavelength λ_max of light emitted by a dense object to its temperature T, can be represented by: