Question 1

As a beam of light travels from one medium to another,the change in direction of the beam of light depends on:

Accepted Answer

A) the wavelength of the light 
B) the index of refraction of the outgoing medium 
C) the index of refraction of the incoming medium 
D) the angle of incidence 
E) all of the above 
A) the wavelength of the light 
B) the index of refraction of the outgoing medium 
C) the index of refraction of the incoming medium 
D) the angle of incidence 
E) all of the above E

Question 2

Most modern spectrographs use a _________ to disperse the light from an object.

Accepted Answer

A) spherical mirror 
B) lens 
C) glass prism 
D) diffraction grating 
E) parabolic mirror 
A) spherical mirror 
B) lens 
C) glass prism 
D) diffraction grating 
E) parabolic mirror D

Question 3

Which of the following cannot be directly detected using a telescope?

Accepted Answer

A) X-rays 
B) visible light 
C) infrared light 
D) neutrinos 
E) ultraviolet light 
A) X-rays 
B) visible light 
C) infrared light 
D) neutrinos 
E) ultraviolet light D

Question 4

Large reflecting telescopes have mirrors that are _________ in shape.

Accepted Answer

A) spherical 
B) parabolic 
C) convex 
D) hyperbolic 
E) cylindrical 
A) spherical 
B) parabolic 
C) convex 
D) hyperbolic 
E) cylindrical

Question 5

Explain why chromatic aberration is a problem for refracting mirrors but not reflecting mirrors.

Accepted Answer

Chromatic aberration occurs because refr

Question 6

Chromatic aberration results from:

Accepted Answer

A) blue light being reflected more than red light 
B) red light being reflected more than blue light 
C) red light being refracted more than blue light 
D) blue light being refracted more than red light 
E) a lens being polished incorrectly 
A) blue light being reflected more than red light 
B) red light being reflected more than blue light 
C) red light being refracted more than blue light 
D) blue light being refracted more than red light 
E) a lens being polished incorrectly

Question 7

Before CCDs were invented,what was the device most commonly used for imaging with optical telescopes?

Accepted Answer

A) Polaroid cameras 
B) photographic glass plates 
C) 35-mm film 
D) high-speed film 
E) video cameras 
A) Polaroid cameras 
B) photographic glass plates 
C) 35-mm film 
D) high-speed film 
E) video cameras

Question 8

How does the resolution of a telescope depend on its focal length?

Accepted Answer

A) The longer the focal length,the better the resolution. 
B) The longer the focal length,the worse the resolution. 
C) There is no relation between resolution and focal length. 
A) The longer the focal length,the better the resolution. 
B) The longer the focal length,the worse the resolution. 
C) There is no relation between resolution and focal length.

Question 9

Water vapor in Earth's atmosphere primarily easily absorbs which type of photons?

Accepted Answer

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

Question 10

One reason to prefer a reflecting over a refracting telescope is:

Accepted Answer

A) its lack of chromatic aberration 
B) its shorter length for the same aperture size 
C) there is no aperture limit 
D) its lighter weight for larger apertures 
E) all of the above are valid reasons 
A) its lack of chromatic aberration 
B) its shorter length for the same aperture size 
C) there is no aperture limit 
D) its lighter weight for larger apertures 
E) all of the above are valid reasons

Question 11

The angular resolution of the largest single-dish radio telescope in the United States,the 100-m Green Bank Telescope,is _________ when it operates at a wavelength of 20 cm.

Accepted Answer

A) 41 arcmin 
B) 6.8 arcmin 
C) 4.1 arcmin 
D) 6.8 arcsec 
E) 4.1 arcsec 
A) 41 arcmin 
B) 6.8 arcmin 
C) 4.1 arcmin 
D) 6.8 arcsec 
E) 4.1 arcsec

Question 12

Unlike photons,neutrinos are relatively easy to detect.

Accepted Answer

A) True 
 B)False

Question 13

Explain three major advantages of CCDs over other imaging techniques.

Accepted Answer

These are possible answers:
(1)They have

Question 14

Why do reflecting telescopes use curved mirrors instead of flat mirrors?

Accepted Answer

The purpose of a telescope is to redirec

Question 15

Why can a compound lens combat a refracting telescope's chromatic aberration?

Accepted Answer

A) Red light is absorbed by a larger amount than blue light. 
B) Red light is refracted by a larger amount than blue light. 
C) Blue light is refracted by a larger amount than red light. 
D) Blue light is absorbed by a larger amount than red light. 
E) A compound lens cannot combat chromatic aberration. 
A) Red light is absorbed by a larger amount than blue light. 
B) Red light is refracted by a larger amount than blue light. 
C) Blue light is refracted by a larger amount than red light. 
D) Blue light is absorbed by a larger amount than red light. 
E) A compound lens cannot combat chromatic aberration.

Question 16

Which of the following is the biggest disadvantage of putting a telescope in space?

Accepted Answer

A) Astronomers don't have as much control in choosing what to observe. 
B) Astronomers have to wait until the telescopes come back to Earth to get their images. 
C) Space telescopes can only observe in certain parts of the electromagnetic spectrum. 
D) Space telescopes don't last long before they fall back down to Earth. 
E) Space telescopes are much more expensive than similar ground-based telescopes. 
A) Astronomers don't have as much control in choosing what to observe. 
B) Astronomers have to wait until the telescopes come back to Earth to get their images. 
C) Space telescopes can only observe in certain parts of the electromagnetic spectrum. 
D) Space telescopes don't last long before they fall back down to Earth. 
E) Space telescopes are much more expensive than similar ground-based telescopes.

Question 17

Where is the best place to put a ground-based optical telescope? Discuss the reasons for your selection.

Accepted Answer

Mountaintops away from cities and in dry

Question 18

A beam of light passes from air to water at an incident angle of 40°,relative to a plane perpendicular to the boundary between the two.At what angle will it emerge into the water,relative to a plane perpendicular to the boundary?

Accepted Answer

A) less than 40° 
B) exactly 40° 
C) more than 40° 
D) The beam of light does not emerge from the water. 
E) There is not enough information to answer the question. 
A) less than 40° 
B) exactly 40° 
C) more than 40° 
D) The beam of light does not emerge from the water. 
E) There is not enough information to answer the question.

Question 19

How much larger is the light-gathering power of a 10-inch telescope than the human eye?

Accepted Answer

Light-gathering power is proportional to

Question 20

Which of the following was NOT discovered by Galileo using a telescope?

Accepted Answer

A) The Moon has a heavily cratered surface. 
B) Jupiter has four moons that orbit around it. 
C) Mars has a polar ice cap similar to the Earth. 
D) The planet Venus goes through phases similar to those of the Moon. 
E) The Milky Way is a collection of countless numbers of individual stars. 
A) The Moon has a heavily cratered surface. 
B) Jupiter has four moons that orbit around it. 
C) Mars has a polar ice cap similar to the Earth. 
D) The planet Venus goes through phases similar to those of the Moon. 
E) The Milky Way is a collection of countless numbers of individual stars.

Exam 6: The Tools of the Astronomer

As a beam of light travels from one medium to another,the change in direction of the beam of light depends on:

Most modern spectrographs use a _________ to disperse the light from an object.

Which of the following cannot be directly detected using a telescope?

Large reflecting telescopes have mirrors that are _________ in shape.

Explain why chromatic aberration is a problem for refracting mirrors but not reflecting mirrors.

Chromatic aberration results from:

Before CCDs were invented,what was the device most commonly used for imaging with optical telescopes?

How does the resolution of a telescope depend on its focal length?

Water vapor in Earth's atmosphere primarily easily absorbs which type of photons?

One reason to prefer a reflecting over a refracting telescope is:

The angular resolution of the largest single-dish radio telescope in the United States,the 100-m Green Bank Telescope,is _________ when it operates at a wavelength of 20 cm.

Unlike photons,neutrinos are relatively easy to detect.

Explain three major advantages of CCDs over other imaging techniques.

Why do reflecting telescopes use curved mirrors instead of flat mirrors?

Why can a compound lens combat a refracting telescope's chromatic aberration?

Which of the following is the biggest disadvantage of putting a telescope in space?

Where is the best place to put a ground-based optical telescope? Discuss the reasons for your selection.

A beam of light passes from air to water at an incident angle of 40°,relative to a plane perpendicular to the boundary between the two.At what angle will it emerge into the water,relative to a plane perpendicular to the boundary?

How much larger is the light-gathering power of a 10-inch telescope than the human eye?

Which of the following was NOT discovered by Galileo using a telescope?

Why Learn Astronomy

Patterns in the Skymotions of Earth

Motion of Astronomical Bodies

Gravity and Orbits

Light

The Birth and Evolution of Planetary Systems

The Terrestrial Planets and Earths Moon

Atmospheres of the Terrestrial Planets

Worlds of Gas and Liquid the Giant Planets

Planetary Adornments Moons and Rings

Dwarf Planets and Small Solar System Bodies

Taking the Measure of Stars

Our Starthe Sun

Star Formation and the Interstellar Medium

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

Relativity and Black Holes

The Expanding Universe

Galaxies

The Milky Waya Normal Spiral Galaxy

Modern Cosmology

Large-Scale Structure in the Universe

Life

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