Question 1

Compared with the speed of visible light in a vacuum (or in space),the speed of visible light in water or in glass is:

Accepted Answer

A)  faster. 
B)  slower. 
C)  exactly the same because the speed of light cannot vary. 
D)  much faster. 
A)  faster. 
B)  slower. 
C)  exactly the same because the speed of light cannot vary. 
D)  much faster.

Question 2

What is the maximum angular resolution (sharpness of the image)obtainable with radio telescopes on Earth?

Accepted Answer

A)  0.00001 arc second using the worldwide very-long-baseline interferometry (VLBI) array of telescope 
B)  100 arc seconds using the 305-m Arecibo telescope in Puerto Rico 
C)  0.0001 arc second using the very-long-baseline array of telescopes extending across the United States and including Hawaii 
D)  0.1 arc second using the 27-dish Very Large Array (VL
A)  of radio telescopes at Socorro, New Mexico 
A)  0.00001 arc second using the worldwide very-long-baseline interferometry (VLBI) array of telescope 
B)  100 arc seconds using the 305-m Arecibo telescope in Puerto Rico 
C)  0.0001 arc second using the very-long-baseline array of telescopes extending across the United States and including Hawaii 
D)  0.1 arc second using the 27-dish Very Large Array (VL
A)  of radio telescopes at Socorro, New Mexico

Question 3

What is refraction of light?

Accepted Answer

A)  the breaking of white light into its composite colors 
B)  the change in direction of a light ray when it reflects on a material that is denser than the one in which it is traveling 
C)  the absorption of light as it traverses a dense, transparent material 
D)  the change in direction of a light ray as it passes at an angle from one transparent material to another that has a different optical density 
A)  the breaking of white light into its composite colors 
B)  the change in direction of a light ray when it reflects on a material that is denser than the one in which it is traveling 
C)  the absorption of light as it traverses a dense, transparent material 
D)  the change in direction of a light ray as it passes at an angle from one transparent material to another that has a different optical density

Question 4

The prime focus of a reflecting telescope is reached by light after:

Accepted Answer

A)  one reflection. 
B)  refraction through one lens and reflection at one mirror. 
C)  reflection at two mirrors. 
D)  refraction at one lens. 
A)  one reflection. 
B)  refraction through one lens and reflection at one mirror. 
C)  reflection at two mirrors. 
D)  refraction at one lens.

Question 5

A Cassegrain telescope has a primary mirror with a 5-m diameter and a hole with a diameter of 5 cm through the primary mirror.By what percentage is the light-gathering power of the mirror reduced because of the hole?

Accepted Answer

A)  0.01% 
B)  1% 
C)  20% 
D)  50% 
A)  0.01% 
B)  1% 
C)  20% 
D)  50%

Question 6

What length of time passes from Jupiter being at superior conjunction and next being at opposition?

Accepted Answer

A)  slightly less than six months 
B)  exactly six months 
C)  slightly more than six months 
D)  almost six years 
A)  slightly less than six months 
B)  exactly six months 
C)  slightly more than six months 
D)  almost six years

Question 7

Which characteristic property of a glass lens is the MOST important in bending light rays to form a focused image?

Accepted Answer

A)  the color of the glass 
B)  the curvature and shape of its surfaces 
C)  the thickness of the center of the lens 
D)  the diameter or size of the lens 
A)  the color of the glass 
B)  the curvature and shape of its surfaces 
C)  the thickness of the center of the lens 
D)  the diameter or size of the lens

Question 8

In the seventeenth century,Isaac Newton suggested a particle theory for light and Christian Huygens proposed a wave theory.Our present understanding is that:

Accepted Answer

A)  the wave theory is correct but the particle theory is not. 
B)  the particle theory is correct but the wave theory is not. 
C)  neither theory provides a correct description of light. 
D)  a combination of both theories is necessary to provide a correct description of light. 
A)  the wave theory is correct but the particle theory is not. 
B)  the particle theory is correct but the wave theory is not. 
C)  neither theory provides a correct description of light. 
D)  a combination of both theories is necessary to provide a correct description of light.

Question 9

Ionization of an atom occurs when:

Accepted Answer

A)  an electron is removed from the atom. 
B)  the nucleus is split, or fission occurs. 
C)  an electron is lifted from the ground state to an excited level. 
D)  an electron drops from a higher energy level to the ground state. 
A)  an electron is removed from the atom. 
B)  the nucleus is split, or fission occurs. 
C)  an electron is lifted from the ground state to an excited level. 
D)  an electron drops from a higher energy level to the ground state.

Question 10

When a ray of light strikes a smooth mirror surface at an angle to the perpendicular,the ray is reflected:

Accepted Answer

A)  on the "other" side of the perpendicular but at the same angle as the incoming ray. 
B)  in reverse along its original (incoming) path. 
C)  at various angles, depending on wavelength. 
D)  so that it travels along the perpendicular to the surface of the mirror. 
A)  on the "other" side of the perpendicular but at the same angle as the incoming ray. 
B)  in reverse along its original (incoming) path. 
C)  at various angles, depending on wavelength. 
D)  so that it travels along the perpendicular to the surface of the mirror.

Question 11

A scientist reports that his measurement of the temperature of the surface of a newly discovered planet is -20 K.What conclusion can you draw from this report?

Accepted Answer

A)  The scientist measured only the dark side of the planet, away from the Sun. 
B)  The planet has no atmosphere. 
C)  The planet is a very long way from the Sun. 
D)  The result is erroneous because absolute temperature cannot be negative. 
A)  The scientist measured only the dark side of the planet, away from the Sun. 
B)  The planet has no atmosphere. 
C)  The planet is a very long way from the Sun. 
D)  The result is erroneous because absolute temperature cannot be negative.

Question 12

Images from the 5-meter telescope at Mt.Palomar are NOT as clear as they were when the telescope was first put into operation over 60 years ago.Why is this?

Accepted Answer

A)  The quality of the mirror has degraded significantly over time. 
B)  Precession has changed the positions of a number of important targets so that they are no longer accessible from Palomar. 
C)  The telescope was recently damaged by an earthquake. 
D)  Light pollution has increased significantly in the past 60 years. 
A)  The quality of the mirror has degraded significantly over time. 
B)  Precession has changed the positions of a number of important targets so that they are no longer accessible from Palomar. 
C)  The telescope was recently damaged by an earthquake. 
D)  Light pollution has increased significantly in the past 60 years.

Question 13

Proper motion is the motion:

Accepted Answer

A)  of a star or other object across (at right angles to) the line of sight. 
B)  of a star or other object along the line of sight, toward or away from us. 
C)  allowed by the laws of physics. 
D)  of a star or other object in any direction through space. 
A)  of a star or other object across (at right angles to) the line of sight. 
B)  of a star or other object along the line of sight, toward or away from us. 
C)  allowed by the laws of physics. 
D)  of a star or other object in any direction through space.

Question 14

Devices to detect X-rays once they have been focused include all but one of the following.Which is the exception?

Accepted Answer

A)  CCDs 
B)  scintillators 
C)  calorimeters 
D)  Schmidt corrector plates 
A)  CCDs 
B)  scintillators 
C)  calorimeters 
D)  Schmidt corrector plates

Question 15

It is difficult to do infrared astronomy at sea level primarily because of what component in Earth's atmosphere?

Accepted Answer

A)  chlorofluorocarbons (CFCs) 
B)  water vapor 
C)  ozone 
D)  carbon dioxide 
A)  chlorofluorocarbons (CFCs) 
B)  water vapor 
C)  ozone 
D)  carbon dioxide

Question 16

Chromatic aberration occurs in a refracting telescope when:

Accepted Answer

A)  the different colors of light do not focus at the same point. 
B)  some wavelengths are scattered out of the telescope by imperfections in the glass in the lenses or are reflected back by the front surface of the lens. 
C)  the lenses bend under their own weight, distorting the final image. 
D)  light from some wavelengths is absorbed by the lenses, distorting the colors of objects. 
A)  the different colors of light do not focus at the same point. 
B)  some wavelengths are scattered out of the telescope by imperfections in the glass in the lenses or are reflected back by the front surface of the lens. 
C)  the lenses bend under their own weight, distorting the final image. 
D)  light from some wavelengths is absorbed by the lenses, distorting the colors of objects.

Question 17

Which of the following wave effects is electromagnetic in nature?

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 18

How do the nuclei of the isotopes ¹⁴C of carbon and ¹⁴N of nitrogen differ from each other?

Accepted Answer

A)  The nuclei have the same number of protons but a different number of neutrons. 
B)  The nuclei are identical; the isotopes differ only in the number of electrons. 
C)  The nuclei have different numbers of both protons and neutrons. 
D)  The nuclei have the same number of neutrons but a different number of protons. 
A)  The nuclei have the same number of protons but a different number of neutrons. 
B)  The nuclei are identical; the isotopes differ only in the number of electrons. 
C)  The nuclei have different numbers of both protons and neutrons. 
D)  The nuclei have the same number of neutrons but a different number of protons.

Question 19

Which method did Ole Rømer use to show that light did NOT travel at infinite speed?

Accepted Answer

A)  Rømer observed that eclipses of Jupiter's satellites by the planet appeared to occur later, when Earth was farther away from Jupiter, because of the travel time for light over the extra distance. 
B)  Rømer measured a time delay between the instant that he sent a flash of light to a mirror on a distant hill and the return of the flash after reflection. 
C)  Rømer carried out a laboratory experiment in which a light beam was sent through an opaque, rotating disk with holes in it and reflected from a distant mirror, where the returning beam did not return through the same hole from which it left because of the travel time for light. 
D)  Rømer measured a 2-second delay between the time of the outgoing pulse of light sent from Earth to the Moon and the time of the returning light pulse after reflection from the Moon. 
A)  Rømer observed that eclipses of Jupiter's satellites by the planet appeared to occur later, when Earth was farther away from Jupiter, because of the travel time for light over the extra distance. 
B)  Rømer measured a time delay between the instant that he sent a flash of light to a mirror on a distant hill and the return of the flash after reflection. 
C)  Rømer carried out a laboratory experiment in which a light beam was sent through an opaque, rotating disk with holes in it and reflected from a distant mirror, where the returning beam did not return through the same hole from which it left because of the travel time for light. 
D)  Rømer measured a 2-second delay between the time of the outgoing pulse of light sent from Earth to the Moon and the time of the returning light pulse after reflection from the Moon.

Question 20

Compared with the mass of an electron,the mass of a proton is:

Accepted Answer

A)  almost 2000 times greater. 
B)  about twice as great. 
C)  about the same. 
D)  about 1/2000 as great. 
A)  almost 2000 times greater. 
B)  about twice as great. 
C)  about the same. 
D)  about 1/2000 as great.

Compared with the speed of visible light in a vacuum (or in space),the speed of visible light in water or in glass is:

What is the maximum angular resolution (sharpness of the image)obtainable with radio telescopes on Earth?

What is refraction of light?

The prime focus of a reflecting telescope is reached by light after:

A Cassegrain telescope has a primary mirror with a 5-m diameter and a hole with a diameter of 5 cm through the primary mirror.By what percentage is the light-gathering power of the mirror reduced because of the hole?

What length of time passes from Jupiter being at superior conjunction and next being at opposition?

Which characteristic property of a glass lens is the MOST important in bending light rays to form a focused image?

In the seventeenth century,Isaac Newton suggested a particle theory for light and Christian Huygens proposed a wave theory.Our present understanding is that:

Ionization of an atom occurs when:

When a ray of light strikes a smooth mirror surface at an angle to the perpendicular,the ray is reflected:

A scientist reports that his measurement of the temperature of the surface of a newly discovered planet is -20 K.What conclusion can you draw from this report?

Images from the 5-meter telescope at Mt.Palomar are NOT as clear as they were when the telescope was first put into operation over 60 years ago.Why is this?

Proper motion is the motion:

Devices to detect X-rays once they have been focused include all but one of the following.Which is the exception?

It is difficult to do infrared astronomy at sea level primarily because of what component in Earth's atmosphere?

Chromatic aberration occurs in a refracting telescope when:

Which of the following wave effects is electromagnetic in nature?

How do the nuclei of the isotopes ¹⁴C of carbon and ¹⁴N of nitrogen differ from each other?

Which method did Ole Rømer use to show that light did NOT travel at infinite speed?

Compared with the mass of an electron,the mass of a proton is:

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Formation of the Solar System and Other Planetary Systems

Exoplanets

The Terrestrial Planets and Their Moons

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

Characterizing Stars

The Lives of the Stars From Birth Through Middle Age

The Deaths and Remnants of Stars

The Galaxies

Cosmology

Astrobiology

Filters

Exam 3: Light and Telescopes

Compared with the speed of visible light in a vacuum (or in space),the speed of visible light in water or in glass is:

What is the maximum angular resolution (sharpness of the image)obtainable with radio telescopes on Earth?

What is refraction of light?

The prime focus of a reflecting telescope is reached by light after:

A Cassegrain telescope has a primary mirror with a 5-m diameter and a hole with a diameter of 5 cm through the primary mirror.By what percentage is the light-gathering power of the mirror reduced because of the hole?

What length of time passes from Jupiter being at superior conjunction and next being at opposition?

Which characteristic property of a glass lens is the MOST important in bending light rays to form a focused image?

In the seventeenth century,Isaac Newton suggested a particle theory for light and Christian Huygens proposed a wave theory.Our present understanding is that:

Ionization of an atom occurs when:

When a ray of light strikes a smooth mirror surface at an angle to the perpendicular,the ray is reflected:

A scientist reports that his measurement of the temperature of the surface of a newly discovered planet is -20 K.What conclusion can you draw from this report?

Images from the 5-meter telescope at Mt.Palomar are NOT as clear as they were when the telescope was first put into operation over 60 years ago.Why is this?

Proper motion is the motion:

Devices to detect X-rays once they have been focused include all but one of the following.Which is the exception?

It is difficult to do infrared astronomy at sea level primarily because of what component in Earth's atmosphere?

Chromatic aberration occurs in a refracting telescope when:

Which of the following wave effects is electromagnetic in nature?

How do the nuclei of the isotopes ¹⁴C of carbon and ¹⁴N of nitrogen differ from each other?

Which method did Ole Rømer use to show that light did NOT travel at infinite speed?

Compared with the mass of an electron,the mass of a proton is:

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Formation of the Solar System and Other Planetary Systems

Exoplanets

The Terrestrial Planets and Their Moons

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

Characterizing Stars

The Lives of the Stars From Birth Through Middle Age

The Deaths and Remnants of Stars

The Galaxies

Cosmology

Astrobiology

Filters