Question 1

Chromatic aberration is the failure of a telescope objective lens to bring all colors of light to the same focus and appears in

Accepted Answer

A)  only a reflecting telescope. 
B)  both reflecting and refracting telescopes. 
C)  all telescopes because it is caused by a basic property of light. 
D)  only a refracting telescope. 
A)  only a reflecting telescope. 
B)  both reflecting and refracting telescopes. 
C)  all telescopes because it is caused by a basic property of light. 
D)  only a refracting telescope.

Question 2

Which of these wave effects is electromagnetic?

Accepted Answer

A)  gravitational wave 
B)  cosmic ray proton 
C)  microwave 
D)  sound wave 
A)  gravitational wave 
B)  cosmic ray proton 
C)  microwave 
D)  sound wave

Question 3

One difference between violet light and red light is that

Accepted Answer

A)  violet light travels faster than red light, even in a vacuum. 
B)  violet light has a shorter wavelength than red light. 
C)  violet light is hotter than red light. 
D)  photons of violet light have less energy than photons of red light. 
A)  violet light travels faster than red light, even in a vacuum. 
B)  violet light has a shorter wavelength than red light. 
C)  violet light is hotter than red light. 
D)  photons of violet light have less energy than photons of red light.

Question 4

If two photons in a vacuum have different energies, what can be said about the wavelengths of the photons?

Accepted Answer

A)  The higher-energy photon has the shorter wavelength. 
B)  The higher-energy photon has the longer wavelength. 
C)  The two photons have the same wavelength; all photons have the same wavelength, regardless of energy. 
D)  We cannot say anything; wavelength depends only on color, not on energy. 
A)  The higher-energy photon has the shorter wavelength. 
B)  The higher-energy photon has the longer wavelength. 
C)  The two photons have the same wavelength; all photons have the same wavelength, regardless of energy. 
D)  We cannot say anything; wavelength depends only on color, not on energy.

Question 5

A particular reflecting telescope has an objective mirror with a focal length of 1.2 m and an eyepiece lens of focal length 6 mm. What is the magnifying power of this telescope?

Accepted Answer

A)  200× 
B)  20× 
C)  2000× 
D)  5× 
A)  200× 
B)  20× 
C)  2000× 
D)  5×

Question 6

Visible light occupies what position in the electromagnetic spectrum?

Accepted Answer

A)  between radio and infrared radiation 
B)  between infrared and ultraviolet 
C)  between infrared and microwave 
D)  between ultraviolet and X-ray 
A)  between radio and infrared radiation 
B)  between infrared and ultraviolet 
C)  between infrared and microwave 
D)  between ultraviolet and X-ray

Question 7

Which of these items poses the greatest hazard to energy grids on Earth?

Accepted Answer

A)  low-energy cosmic rays emitted by the Sun 
B)  X-rays originating from the Sun 
C)  gamma rays from active galactic nuclei 
D)  ultrahigh-energy cosmic rays 
A)  low-energy cosmic rays emitted by the Sun 
B)  X-rays originating from the Sun 
C)  gamma rays from active galactic nuclei 
D)  ultrahigh-energy cosmic rays

Question 8

Why do astronomers require measurements from at least three gravitational wave detectors to identify the source of a gravitational radiation signal?

Accepted Answer

A)  Gravitational waves have a wavelength of about a thousand kilometers, requiring detections across large distances. 
B)  Gravitational waves are so weak that several detectors are required to confirm a signal. 
C)  Three detections are required to separate real gravitational waves from locally generated noise. 
D)  The time delay between the different detectors allows astronomers to identify the direction of the source. 
A)  Gravitational waves have a wavelength of about a thousand kilometers, requiring detections across large distances. 
B)  Gravitational waves are so weak that several detectors are required to confirm a signal. 
C)  Three detections are required to separate real gravitational waves from locally generated noise. 
D)  The time delay between the different detectors allows astronomers to identify the direction of the source.

Question 9

One way to distinguish a star from a planet, particularly when they appear near the horizon, is that stars appear to twinkle and planets shine steadily. Which of these statements is a reasonable explanation for this phenomenon?

Accepted Answer

A)  Stars actually do twinkle-shine with a light that flickers bright and dim-whereas planets shine with a steady, unwavering light. 
B)  The light from planets is so much brighter than the light from stars (when they are observed from Earth) that it is unaffected by air movement in Earth's atmosphere. 
C)  The disk of a planet, as observed from Earth, appears larger than the disk of a star. Thus, if refraction through moving air in Earth's atmosphere makes the planet's disk appear to move about slightly, there will normally be a central part of the disk that shines steadily and does not appear to twinkle. 
D)  Because light from planets is reflected, it is unaffected by the refraction in Earth's atmosphere. 
A)  Stars actually do twinkle-shine with a light that flickers bright and dim-whereas planets shine with a steady, unwavering light. 
B)  The light from planets is so much brighter than the light from stars (when they are observed from Earth) that it is unaffected by air movement in Earth's atmosphere. 
C)  The disk of a planet, as observed from Earth, appears larger than the disk of a star. Thus, if refraction through moving air in Earth's atmosphere makes the planet's disk appear to move about slightly, there will normally be a central part of the disk that shines steadily and does not appear to twinkle. 
D)  Because light from planets is reflected, it is unaffected by the refraction in Earth's atmosphere.

Question 10

What is the main optical element of a refracting telescope?

Accepted Answer

A)  plane (flat) mirror 
B)  curved mirror 
C)  Prism 
D)  Lens 
A)  plane (flat) mirror 
B)  curved mirror 
C)  Prism 
D)  Lens

Question 11

What are the basic parts of a Schmidt-Cassegrain telescope?

Accepted Answer

A)  spherical, concave primary mirror, and glass corrector plate 
B)  parabolic, concave primary mirror, and convex secondary mirror 
C)  parabolic, concave primary mirror, and concave secondary mirror 
D)  parabolic, concave primary mirror, and flat, diagonal secondary mirror 
A)  spherical, concave primary mirror, and glass corrector plate 
B)  parabolic, concave primary mirror, and convex secondary mirror 
C)  parabolic, concave primary mirror, and concave secondary mirror 
D)  parabolic, concave primary mirror, and flat, diagonal secondary mirror

Question 12

What is the purpose of the glass corrector plate at the front of a Schmidt telescope?

Accepted Answer

A)  The plate reflects unwanted wavelengths away from the primary mirror. 
B)  The plate corrects for spherical aberration in the primary mirror. 
C)  The plate corrects for chromatic aberration in the primary mirror. 
D)  The plate corrects for sagging of the primary mirror under its own weight when the telescope is turned at an angle to the vertical. 
A)  The plate reflects unwanted wavelengths away from the primary mirror. 
B)  The plate corrects for spherical aberration in the primary mirror. 
C)  The plate corrects for chromatic aberration in the primary mirror. 
D)  The plate corrects for sagging of the primary mirror under its own weight when the telescope is turned at an angle to the vertical.

Question 13

A beam of light of which of these pure colors is made up of photons of the highest energy?

Accepted Answer

A)  red 
B)  yellow 
C)  green 
D)  blue 
A)  red 
B)  yellow 
C)  green 
D)  blue

Question 14

If one sends white light through a prism to produce a spectrum, and then sends this entire spectrum through a lens to recombine it, the result will be

Accepted Answer

A)  red. 
B)  yellow. 
C)  white. 
D)  black (no light). 
A)  red. 
B)  yellow. 
C)  white. 
D)  black (no light).

Question 15

Some research telescopes have secondary mirrors that block the central part of the larger primary mirror. What problem does this introduce for observations?

Accepted Answer

A)  Because the secondary mirror blocks part of the primary, there is a hole in the center of the resulting image. 
B)  Because the secondary mirror diverts light away from the original path, it distorts the image. 
C)  Because the secondary mirror blocks part of the primary, the image is darker. 
D)  There is no disadvantage to this arrangement. 
A)  Because the secondary mirror blocks part of the primary, there is a hole in the center of the resulting image. 
B)  Because the secondary mirror diverts light away from the original path, it distorts the image. 
C)  Because the secondary mirror blocks part of the primary, the image is darker. 
D)  There is no disadvantage to this arrangement.

Question 16

Which of these optical elements or combinations make up a Newtonian telescope?

Accepted Answer

A)  two curved mirrors, one concave, the second convex 
B)  two lenses, to produce an image the correct way around 
C)  one concave and one flat mirror 
D)  one concave focusing mirror 
A)  two curved mirrors, one concave, the second convex 
B)  two lenses, to produce an image the correct way around 
C)  one concave and one flat mirror 
D)  one concave focusing mirror

Question 17

How much more efficient in collecting incoming photons is the modern charge-coupled device (CCD) compared to a typical photographic plate?

Accepted Answer

A)  about 10 times 
B)  more than 100 times 
C)  a little better than a factor of 2 
D)  about 35 times 
A)  about 10 times 
B)  more than 100 times 
C)  a little better than a factor of 2 
D)  about 35 times

Question 18

The main reason for placing a telescope and scientific equipment into an aircraft to carry out infrared astronomy is to

Accepted Answer

A)  obtain photographs of resolution higher than can be obtained on the ground. 
B)  avoid stray IR radiation from the warm Earth and its occupants. 
C)  avoid the absorption of the IR radiation by water vapor. 
D)  obtain longer observing times on specific sources by moving in the direction of Earth's rotation. 
A)  obtain photographs of resolution higher than can be obtained on the ground. 
B)  avoid stray IR radiation from the warm Earth and its occupants. 
C)  avoid the absorption of the IR radiation by water vapor. 
D)  obtain longer observing times on specific sources by moving in the direction of Earth's rotation.

Question 19

The highest-energy cosmic rays detected on Earth have energies comparable to

Accepted Answer

A)  the most energetic radio photons. 
B)  a car traveling at 60 miles per hour. 
C)  a baseball thrown by a major league pitcher. 
D)  a supernova. 
A)  the most energetic radio photons. 
B)  a car traveling at 60 miles per hour. 
C)  a baseball thrown by a major league pitcher. 
D)  a supernova.

Question 20

Compared to the direction of the incoming light, in which way does the light leave the eyepiece of a Newtonian telescope?

Accepted Answer

A)  at a variable angle depending on the direction of the source in the sky 
B)  in the same direction 
C)  in the reverse direction, back toward the source 
D)  at right angles 
A)  at a variable angle depending on the direction of the source in the sky 
B)  in the same direction 
C)  in the reverse direction, back toward the source 
D)  at right angles

Chromatic aberration is the failure of a telescope objective lens to bring all colors of light to the same focus and appears in

Which of these wave effects is electromagnetic?

One difference between violet light and red light is that

If two photons in a vacuum have different energies, what can be said about the wavelengths of the photons?

A particular reflecting telescope has an objective mirror with a focal length of 1.2 m and an eyepiece lens of focal length 6 mm. What is the magnifying power of this telescope?

Visible light occupies what position in the electromagnetic spectrum?

Which of these items poses the greatest hazard to energy grids on Earth?

Why do astronomers require measurements from at least three gravitational wave detectors to identify the source of a gravitational radiation signal?

One way to distinguish a star from a planet, particularly when they appear near the horizon, is that stars appear to twinkle and planets shine steadily. Which of these statements is a reasonable explanation for this phenomenon?

What is the main optical element of a refracting telescope?

What are the basic parts of a Schmidt-Cassegrain telescope?

What is the purpose of the glass corrector plate at the front of a Schmidt telescope?

A beam of light of which of these pure colors is made up of photons of the highest energy?

If one sends white light through a prism to produce a spectrum, and then sends this entire spectrum through a lens to recombine it, the result will be

Some research telescopes have secondary mirrors that block the central part of the larger primary mirror. What problem does this introduce for observations?

Which of these optical elements or combinations make up a Newtonian telescope?

How much more efficient in collecting incoming photons is the modern charge-coupled device (CCD) compared to a typical photographic plate?

The main reason for placing a telescope and scientific equipment into an aircraft to carry out infrared astronomy is to

The highest-energy cosmic rays detected on Earth have energies comparable to

Compared to the direction of the incoming light, in which way does the light leave the eyepiece of a Newtonian telescope?

Discovering the Night Sky

Gravitation and the Motion of the Planets

Atomic Physics and Spectra

Exoplanets and the Formation of Planetary Systems

Formation of the Solar System

Earth and the Moon

The Other Terrestrial Planets

The Outer Planets

Vagabonds of the Solar System

The Sun: Our Extraordinary Star

Characterizing Stars

The Lives of Stars From Birth Through Middle Age

The Death of Stars

Black Holes: Matters of Gravity

The Milky Way Galaxy

Galaxies

Quasars and Other Active Galaxies

Cosmology

Astrobiology

Filters

Exam 3: Light and Telescopes

Chromatic aberration is the failure of a telescope objective lens to bring all colors of light to the same focus and appears in

Which of these wave effects is electromagnetic?

One difference between violet light and red light is that

If two photons in a vacuum have different energies, what can be said about the wavelengths of the photons?

A particular reflecting telescope has an objective mirror with a focal length of 1.2 m and an eyepiece lens of focal length 6 mm. What is the magnifying power of this telescope?

Visible light occupies what position in the electromagnetic spectrum?

Which of these items poses the greatest hazard to energy grids on Earth?

Why do astronomers require measurements from at least three gravitational wave detectors to identify the source of a gravitational radiation signal?

One way to distinguish a star from a planet, particularly when they appear near the horizon, is that stars appear to twinkle and planets shine steadily. Which of these statements is a reasonable explanation for this phenomenon?

What is the main optical element of a refracting telescope?

What are the basic parts of a Schmidt-Cassegrain telescope?

What is the purpose of the glass corrector plate at the front of a Schmidt telescope?

A beam of light of which of these pure colors is made up of photons of the highest energy?

If one sends white light through a prism to produce a spectrum, and then sends this entire spectrum through a lens to recombine it, the result will be

Some research telescopes have secondary mirrors that block the central part of the larger primary mirror. What problem does this introduce for observations?

Which of these optical elements or combinations make up a Newtonian telescope?

How much more efficient in collecting incoming photons is the modern charge-coupled device (CCD) compared to a typical photographic plate?

The main reason for placing a telescope and scientific equipment into an aircraft to carry out infrared astronomy is to

The highest-energy cosmic rays detected on Earth have energies comparable to

Compared to the direction of the incoming light, in which way does the light leave the eyepiece of a Newtonian telescope?

Discovering the Night Sky

Gravitation and the Motion of the Planets

Atomic Physics and Spectra

Exoplanets and the Formation of Planetary Systems

Formation of the Solar System

Earth and the Moon

The Other Terrestrial Planets

The Outer Planets

Vagabonds of the Solar System

The Sun: Our Extraordinary Star

Characterizing Stars

The Lives of Stars From Birth Through Middle Age

The Death of Stars

Black Holes: Matters of Gravity

The Milky Way Galaxy

Galaxies

Quasars and Other Active Galaxies

Cosmology

Astrobiology

Filters