Question 1

Which of the following statements best describes the two principle advantages of telescopes over eyes?

Accepted Answer

A) Telescopes collect more light and are unaffected by twinkling. 
B) Telescopes have much more magnification and better angular resolution. 
C) Telescopes can collect far more light with far better angular resolution. 
D) Telescopes can collect far more light with far greater magnification. 
A) Telescopes collect more light and are unaffected by twinkling. 
B) Telescopes have much more magnification and better angular resolution. 
C) Telescopes can collect far more light with far better angular resolution. 
D) Telescopes can collect far more light with far greater magnification.

Question 2

Which of the following objects is not a close approximation of a thermal emitter?

Accepted Answer

A) you 
B) a planet 
C) a star 
D) a filament in a light bulb 
E) hot, thin gas 
A) you 
B) a planet 
C) a star 
D) a filament in a light bulb 
E) hot, thin gas

Question 3

Each of the following describes an "Atom 1" and an "Atom 2." In which case are the two atoms different isotopes of the same element?

Accepted Answer

A) Atom 1: nucleus with 4 protons and 5 neutrons, surrounded by 4 electrons; Atom 2: nucleus with 5 protons and 5 neutrons, surrounded by 4 electrons 
B) Atom 1: nucleus with 6 protons and 8 neutrons, surrounded by 6 electrons; Atom 2: nucleus with 7 protons and 8 neutrons, surrounded by 7 electrons 
C) Atom 1: nucleus with 8 protons and 8 neutrons, surrounded by 8 electrons; Atom 2: nucleus with 8 protons and 8 neutrons, surrounded by 7 electrons 
D) Atom 1: nucleus with 7 protons and 8 neutrons, surrounded by 7 electrons; Atom 2: nucleus with 7 protons and 7 neutrons, surrounded by 7 electrons 
A) Atom 1: nucleus with 4 protons and 5 neutrons, surrounded by 4 electrons; Atom 2: nucleus with 5 protons and 5 neutrons, surrounded by 4 electrons 
B) Atom 1: nucleus with 6 protons and 8 neutrons, surrounded by 6 electrons; Atom 2: nucleus with 7 protons and 8 neutrons, surrounded by 7 electrons 
C) Atom 1: nucleus with 8 protons and 8 neutrons, surrounded by 8 electrons; Atom 2: nucleus with 8 protons and 8 neutrons, surrounded by 7 electrons 
D) Atom 1: nucleus with 7 protons and 8 neutrons, surrounded by 7 electrons; Atom 2: nucleus with 7 protons and 7 neutrons, surrounded by 7 electrons

Question 4

State the two laws of thermal radiation.

Accepted Answer

1. Hotter objects emit more ra

Question 5

There are more atoms in a glass of water than stars in the observable universe.

Accepted Answer

A) True 
 B)False

Question 6

The Size of Molecules: You have a small flask of oil. You pour this oil onto a clear, calm pool of water and watch the oil slick spread out slowly with time. Imagine that it is your belief that the oil is not a continuous substance but made of individual particles called "molecules." Assuming this hypothesis is true, can you make a testable prediction on how the oil slick will behave as it spreads? Will this prediction allow you to estimate the size of the "molecules"? Search online to see if there is any evidence that the Greeks attempted such an experiment.

Accepted Answer

If the oil is made of individual molecul

Question 7

The angular separation of two stars is 0.1 arcseconds and you photograph them with a telescope that has an angular resolution of 1 arcsecond. What will you see?

Accepted Answer

A) You will see two distinct stars in your photograph. 
B) The stars will not show up at all in your photograph. 
C) The two stars will appear to be touching, looking rather like a small dumbbell. 
D) The photo will seem to show only one star rather than two. 
A) You will see two distinct stars in your photograph. 
B) The stars will not show up at all in your photograph. 
C) The two stars will appear to be touching, looking rather like a small dumbbell. 
D) The photo will seem to show only one star rather than two.

Question 8

The stars in our sky twinkle in brightness and color because of _.

Accepted Answer

A) rapid changes in the brightnesses and colors of stars caused by changes in their spectra 
B) light pollution 
C) the bubbling and boiling of gases on the surfaces of stars 
D) turbulence in the Earth's atmosphere 
A) rapid changes in the brightnesses and colors of stars caused by changes in their spectra 
B) light pollution 
C) the bubbling and boiling of gases on the surfaces of stars 
D) turbulence in the Earth's atmosphere

Question 9

Which of the following best describes why we say that light is an electromagnetic wave?

Accepted Answer

A) Light can be produced only by electric or magnetic appliances. 
B) The term electromagnetic wave arose for historical reasons, but we now know that light has nothing to do with either electricity or magnetism. 
C) The passage of a light wave can cause electrically charged particles to move up and down. 
D) Light is produced only when massive fields of electric and magnetic energy collide with one another. 
A) Light can be produced only by electric or magnetic appliances. 
B) The term electromagnetic wave arose for historical reasons, but we now know that light has nothing to do with either electricity or magnetism. 
C) The passage of a light wave can cause electrically charged particles to move up and down. 
D) Light is produced only when massive fields of electric and magnetic energy collide with one another.

Question 10

Explain what an interferometer is and give an example.

Accepted Answer

Interferometers are groups of telescopes

Question 11

Doppler shifted hydrogen absorption lines are seen in the spectrum of a star. The hydrogen line at 656.28 nm is seen to be shifted to 656.08 nm. The star is moving at which fraction of the speed of light?

Accepted Answer

A) about 0.03 (3 × 10-2) 
B) about 0.2 
C) about 0.000003 (3 × 10-6) 
D) about 0.0003 (3 ×10-4) 
A) about 0.03 (3 × 10-2) 
B) about 0.2 
C) about 0.000003 (3 × 10-6) 
D) about 0.0003 (3 ×10-4)

Question 12

You and I are emitting primarily

Accepted Answer

A) radio radiation. 
B) infrared radiation. 
C) visual radiation. 
D) X- ray radiation. 
A) radio radiation. 
B) infrared radiation. 
C) visual radiation. 
D) X- ray radiation.

Question 13

Which of the following statements about X- rays and radio waves is not true?

Accepted Answer

A) X- rays travel through space faster than radio waves. 
B) X- rays have higher frequency than radio waves. 
C) X- rays have shorter wavelengths than radio waves. 
D) X- rays and radio waves are both forms of light, or electromagnetic radiation. 
A) X- rays travel through space faster than radio waves. 
B) X- rays have higher frequency than radio waves. 
C) X- rays have shorter wavelengths than radio waves. 
D) X- rays and radio waves are both forms of light, or electromagnetic radiation.

Question 14

A typical atom has a size of about

Accepted Answer

A) 1 picometer (10- 12 meters). 
B) 1 Angstrom (10- 10 meters). 
C) 1 millimeter (10- 3 meters). 
D) 1 nanometer (10- 9 meters). 
A) 1 picometer (10- 12 meters). 
B) 1 Angstrom (10- 10 meters). 
C) 1 millimeter (10- 3 meters). 
D) 1 nanometer (10- 9 meters).

Question 15

If a hydrogen emission line appears at 656.2 nm in the laboratory, what can we say about a cloud of hydrogen gas with this same emission line at 680.2 nm?

Accepted Answer

A) It is neither receding nor approaching us. 
B) The location of the emission line has nothing to do with speed. 
C) It is approaching us. 
D) It is receding away from us. 
A) It is neither receding nor approaching us. 
B) The location of the emission line has nothing to do with speed. 
C) It is approaching us. 
D) It is receding away from us.

Question 16

In what wavelength range was interferometry first routinely used?

Accepted Answer

A) radio 
B) X- ray 
C) infrared 
D) optical 
E) ultraviolet 
A) radio 
B) X- ray 
C) infrared 
D) optical 
E) ultraviolet

Question 17

If we observe one edge of a planet to be redshifted and the opposite edge to be blueshifted, what can we conclude about the planet?

Accepted Answer

A) The planet is actually two bodies, one moving toward us, the other away from us. 
B) The planet is rotating. 
C) The planet is in the process of formation. 
D) The planet is in the process of falling apart. 
A) The planet is actually two bodies, one moving toward us, the other away from us. 
B) The planet is rotating. 
C) The planet is in the process of formation. 
D) The planet is in the process of falling apart.

Question 18

We are measuring the spectra of two hydrogen gas clouds. The laboratory frame wavelength of one hydrogen line is 656.2 nm. Cloud A's emission line wavelength is 660.1 nm and Cloud B's emission line wavelength is 670.1 nm. What can we conclude about these clouds?

Accepted Answer

A) They are both approaching us, and Cloud A is approaching faster than Cloud B. 
B) They are both approaching us, and Cloud B is approaching faster than Cloud A. 
C) They are both receding from us, and Cloud A is receding faster than Cloud B. 
D) They are both receding from us, and Cloud B is receding faster than Cloud A. 
A) They are both approaching us, and Cloud A is approaching faster than Cloud B. 
B) They are both approaching us, and Cloud B is approaching faster than Cloud A. 
C) They are both receding from us, and Cloud A is receding faster than Cloud B. 
D) They are both receding from us, and Cloud B is receding faster than Cloud A.

Question 19

The largest effective telescope, created by radio interferometry, is the diameter of

Accepted Answer

A) Earth. 
B) tens of miles across, in the deserts of New Mexico. 
C) several football fields, in a natural depression in Puerto Rico. 
D) the state of New Mexico. 
E) the continental United States. 
A) Earth. 
B) tens of miles across, in the deserts of New Mexico. 
C) several football fields, in a natural depression in Puerto Rico. 
D) the state of New Mexico. 
E) the continental United States.

Question 20

In order for an atom to absorb a photon (a particle of light),

Accepted Answer

A) the photon must have enough energy to remove an electron from the atom. 
B) the atom must have lost all of its electrons. 
C) the photon must have energy matching the difference in energy between energy levels in the atom. 
D) A or C 
E) B or C 
A) the photon must have enough energy to remove an electron from the atom. 
B) the atom must have lost all of its electrons. 
C) the photon must have energy matching the difference in energy between energy levels in the atom. 
D) A or C 
E) B or C

Which of the following statements best describes the two principle advantages of telescopes over eyes?

Which of the following objects is not a close approximation of a thermal emitter?

Each of the following describes an "Atom 1" and an "Atom 2." In which case are the two atoms different isotopes of the same element?

State the two laws of thermal radiation.

There are more atoms in a glass of water than stars in the observable universe.

The angular separation of two stars is 0.1 arcseconds and you photograph them with a telescope that has an angular resolution of 1 arcsecond. What will you see?

The stars in our sky twinkle in brightness and color because of _.

Which of the following best describes why we say that light is an electromagnetic wave?

Explain what an interferometer is and give an example.

Doppler shifted hydrogen absorption lines are seen in the spectrum of a star. The hydrogen line at 656.28 nm is seen to be shifted to 656.08 nm. The star is moving at which fraction of the speed of light?

You and I are emitting primarily

Which of the following statements about X- rays and radio waves is not true?

A typical atom has a size of about

If a hydrogen emission line appears at 656.2 nm in the laboratory, what can we say about a cloud of hydrogen gas with this same emission line at 680.2 nm?

In what wavelength range was interferometry first routinely used?

If we observe one edge of a planet to be redshifted and the opposite edge to be blueshifted, what can we conclude about the planet?

We are measuring the spectra of two hydrogen gas clouds. The laboratory frame wavelength of one hydrogen line is 656.2 nm. Cloud A's emission line wavelength is 660.1 nm and Cloud B's emission line wavelength is 670.1 nm. What can we conclude about these clouds?

The largest effective telescope, created by radio interferometry, is the diameter of

In order for an atom to absorb a photon (a particle of light),

A Modern View of the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Formation of the Solar System

Earth and the Terrestrial Worlds

Jovian Planet System

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Other Planetary Systems: the New Science of Distant Worlds

Our Star

Surveying the Stars

Star Stuff

The Bizarre Stellar Graveyard

Our Galaxy

A Universe of Galaxies

The Birth of the Universe

Dark Matter, Dark Energy, and the Fate of the Universe

Life in the Universe

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Exam 5: Light: the Cosmic Messenger

Which of the following statements best describes the two principle advantages of telescopes over eyes?

Which of the following objects is not a close approximation of a thermal emitter?

Each of the following describes an "Atom 1" and an "Atom 2." In which case are the two atoms different isotopes of the same element?

State the two laws of thermal radiation.

There are more atoms in a glass of water than stars in the observable universe.

The angular separation of two stars is 0.1 arcseconds and you photograph them with a telescope that has an angular resolution of 1 arcsecond. What will you see?

The stars in our sky twinkle in brightness and color because of _.

Which of the following best describes why we say that light is an electromagnetic wave?

Explain what an interferometer is and give an example.

Doppler shifted hydrogen absorption lines are seen in the spectrum of a star. The hydrogen line at 656.28 nm is seen to be shifted to 656.08 nm. The star is moving at which fraction of the speed of light?

You and I are emitting primarily

Which of the following statements about X- rays and radio waves is not true?

A typical atom has a size of about

If a hydrogen emission line appears at 656.2 nm in the laboratory, what can we say about a cloud of hydrogen gas with this same emission line at 680.2 nm?

In what wavelength range was interferometry first routinely used?

If we observe one edge of a planet to be redshifted and the opposite edge to be blueshifted, what can we conclude about the planet?

We are measuring the spectra of two hydrogen gas clouds. The laboratory frame wavelength of one hydrogen line is 656.2 nm. Cloud A's emission line wavelength is 660.1 nm and Cloud B's emission line wavelength is 670.1 nm. What can we conclude about these clouds?

The largest effective telescope, created by radio interferometry, is the diameter of

In order for an atom to absorb a photon (a particle of light),

A Modern View of the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Formation of the Solar System

Earth and the Terrestrial Worlds

Jovian Planet System

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Other Planetary Systems: the New Science of Distant Worlds

Our Star

Surveying the Stars

Star Stuff

The Bizarre Stellar Graveyard

Our Galaxy

A Universe of Galaxies

The Birth of the Universe

Dark Matter, Dark Energy, and the Fate of the Universe

Life in the Universe

Filters