Universe Solar System Stars and Galaxies 8th Edition by Seeds – Test Bank

Complete Test Bank With Answers

 

 

Sample Questions Posted Below

 

CHAPTER 5—LIGHT AND TELESCOPES

MULTIPLE CHOICE

1. What is the wavelength of the longest wavelength light that can be seen with the human eye?

a. 400 nm

b. 4000 nm

c. 7000 nm

d. 700 nm

e. 3108 m

ANS: D PTS: 1

2. ____ has (have) wavelengths that are longer than visible light.

a. Gamma rays

b. Ultraviolet light

c. Infrared radiation

d. X-rays

e. a, b and d above

ANS: C PTS: 1

3. ____ has (have) wavelengths that are shorter than visible light.

I. Gamma rays

II. Ultraviolet light

III. Infrared radiation

IV. X-rays

a. I & II

b. I & IV

c. II & III

d. II, III, & IV

e. I, II, & IV

ANS: E PTS: 1

4. Astronomers build optical telescopes on tops of mountains because

a. there is less air to dim the light.

b. the seeing is better.

c. CCDs work better with a beautiful mountain view.

d. all of the above.

e. a and b.

ANS: E PTS: 1

5. A ____ has a few million light sensitive diodes in an array typically about a half-inch square.

a. photometer

b. charge-coupled device

c. spectrograph

d. photographic plate

e. grating

ANS: B PTS: 16. 7. 8. 9. 10. 11. Radio telescopes have poor resolving power because

a. their diameters are so large.

b. the energy they receive is not electromagnetic radiation.

c. radio waves have long wavelengths.

d. a and b.

e. none of the above.

ANS: C PTS: 1

Ultraviolet radiation from a star

a. will not penetrate Earth’s atmosphere and reach the ground.

b. has a wavelength that is longer than the visible light emitted by the star.

c. has a wavelength that is shorter than the X-rays emitted by the star.

d. a and b.

e. b and c.

ANS: A PTS: 1

A new generation of ground-based telescopes is currently being built that overcomes the limitations of

the older large telescopes. Some of these new telescopes

a. use segmented mirrors.

b. use mirrors that are very thin.

c. use active optics to control the shape of the mirror.

d. all of the above.

e. none of the above.

ANS: D PTS: 1

Radio telescopes are important in astronomy because

a. they can detect cool hydrogen.

b. they have high magnification.

c. the can detect interstellar dust clouds.

d. they are very inexpensive to build on tops of mountains.

e. they don’t need to be as large as optical telescopes to achieve the same resolving power.

ANS: A PTS: 1

The sidereal drive of a telescope mounting must turn the telescope

a. b. c. d. southward about the polar axis.

eastward about the polar axis.

westward about the polar axis.

northward about the polar axis.

e. none of the above.

ANS: C PTS: 1

Far infrared astronomy must be done from high-flying aircraft because

a. b. c. d. far infrared radiation is absorbed low in Earth’s atmosphere.

far infrared photons are quite energetic.

far infrared telescopes are not very heavy.

far infrared sources are very bright.

e. none of the above.

ANS: A PTS: 112. A ____ is a piece of glass with many small parallel lines etched on its surface to produce a spectrum.

a. grating

b. spectrograph

c. photometer

d. charge-coupled device

e. prism

ANS: A PTS: 1

13. The Very Long Baseline Array (VLBA)

a. b. c. d. e. is the highest resolution optical telescope ever built.

is located in Arecibo, Puerto Rico.

is a matched pair of 8 m telescopes, one of which is in Chile and the other in Hawaii.

is an air-borne infrared telescope.

is a set of radio telescopes linked together electronically to provide very high resolution.

ANS: E PTS: 1

14. The technique of connecting multiple telescopes together to combine the images from each telescope

is known as

a. aberation.

b. resolving power.

c. active optics.

d. adaptive optics.

e. interferometry.

ANS: E PTS: 1

15. Interferometry

a. b. c. d. e. is used to improve the resolving power.

decreases the chromatic aberration of a telescope.

works only for large X-ray and ultraviolet telescopes.

requires that radio telescopes be within a few hundred feet of each other.

is none of the above.

ANS: A PTS: 1

16. The ____ of a telescope is a measure of its ability to show fine detail and depends on the diameter of

the objective.

a. light-gathering power

b. focal length

c. magnifying power

d. resolving power

e. spherical aberration

ANS: D PTS: 1

17. Which of the following telescopes must be used above Earth’s atmosphere?

a. an optical telescope

b. the VLBA telescope

c. an X-ray telescope

d. a radio telescope

e. none of the above

ANS: C PTS: 118. A telescope that suffers from chromatic aberration and has a low light-gathering power is most likely

a. a small-diameter reflecting telescope.

b. a small-diameter refracting telescope.

c. a large-diameter refracting telescope.

d. a large-diameter reflecting telescope.

e. an infrared telescope.

ANS: B PTS: 1

19. The energy of a photon

a. b. c. d. e. is proportional to the wavelength of the light.

is inversely proportional to the wavelength of the light.

depends only on the speed of the light.

depends only on the mass of the photon.

depends on both the mass and speed of the photon.

ANS: B PTS: 1

20. Long wavelength visible light

a. b. c. d. e. will have a greater energy than short wavelength visible light.

will have a speed that is faster than short wavelength light.

has a higher frequency than short wavelength visible light.

will appear blue in color to the average human eye.

will appear red in color to the average human eye.

ANS: E PTS: 1

21. Photons of blue light

a. have a greater energy than photons of red light.

b. have a greater energy than photons of ultraviolet light.

c. have a lower frequency than photons of red light.

d. have a longer wavelength than photons of red light.

e. travel at a greater speed than photons of red light.

ANS: A PTS: 1

22. Which of the following types of electromagnetic radiation has the highest frequency?

a. X-rays

b. visible light

c. radio

d. gamma rays

e. infrared radiation

ANS: D PTS: 1

23. Which of the following types of electromagnetic radiation has the smallest frequency?

a. X-rays

b. visible light

c. radio

d. gamma rays

e. infrared radiation

ANS: C PTS: 1

24. Which of the following types of electromagnetic radiation has the greatest energy?

a. X-raysb. visible light

c. radio

d. gamma rays

e. infrared radiation

ANS: D PTS: 1

25. Which of the following types of electromagnetic radiation has the lowest energy?

a. X-rays

b. visible light

c. ultraviolet

d. gamma rays

e. infrared radiation

ANS: E PTS: 1

26. An achromatic lens

a. is used to correct spherical aberration in reflecting telescopes.

b. is used to correct chromatic aberration in refracting telescopes.

c. is used to correct spherical aberration in refracting telescopes.

d. is used to correct chromatic aberration in reflecting telescopes.

e. contains two mirrors and focuses the light back through the primary mirror.

ANS: B PTS: 1

27. ____ is absorbed by water in Earth’s atmosphere and requires that telescopes for observing at these

wavelengths be placed on mountain tops or in space.

a. Infrared radiation

b. Ultraviolet radiation

c. Radio wave radiation

d. X-ray radiation

e. Visible light

ANS: A PTS: 1

28. ____ is absorbed by ozone in Earth’s atmosphere that is located between 20 km and 40 km above

Earth’s surface. Therefore, telescopes to observe this radiation must be placed in space.

a. Infrared radiation

b. Ultraviolet radiation

c. Radio wave radiation

d. X-ray radiation

e. Visible light

ANS: B PTS: 1

29. Increasing the diameter of a telescope

I. increases its light-gathering power.

II. increases its resolving power.

III. increases it magnifying power.

IV. increases its chromatic aberration.

a. I, II, III, & IV

b. I, II, & III

c. I, II, & IVd. III & IV

e. I & II

ANS: E PTS: 1

30. A nanometer is

a. a unit of frequency.

b. a unit of energy.

c. a unit of mass.

d. a unit of length.

e. a unit of resolving power.

ANS: D PTS: 1

31. The optical shape of segmented mirrors is controlled by computer-driven thrusters under the mirrors in

what is called

a. an achromatic lens.

b. active optics.

c. a Schmidt-Cassegrain design.

d. a Newtonian design.

e. interferometry.

ANS: B PTS: 1

32. The pupil of the human eye is approximately 0.8 cm in diameter when adapted to the dark. The ratio of

the light-gathering power of a 1.6-m telescope to that of the human eye is ____.

a. 2

b. 4

c. 20

d. 400

e. 40,000

ANS: E PTS: 1

33. What is the ratio of the light-gathering power of a 10-m telescope to that of a 1-m telescope?

a. 10 to 1

b. 1 to 10

c. 100 to 1

d. 1 to 100

e. 3.2 to 1

ANS: C PTS: 1

34. The resolving power for light of 550 nm of an optical telescope with a diameter of 232 cm is

a. 0.05 arc seconds.

b. 232 arc seconds.

c. 2.32 arc seconds.

d. 5 arc seconds.

e. 11.6 arc seconds.

ANS: A PTS: 1

35. What is the magnification of a telescope and eyepiece if the telescope objective has a focal length of

200 cm and the eyepiece has a focal length of 2.0 cm?

a. 400 times

b. 4000 times36. 37. 38. 39. 40. 41. c. 100 times

d. 1000 times

e. 40 times

ANS: C PTS: 1

What is the wavelength of light that has a frequency of 3 MHz?

a. 91014 Hz

b. 11014 m

c. 91014 m

d. 100 m

e. 0.01 m

ANS: D PTS: 1

What is the frequency of the shortest wavelength light that can be detected by the average human eye?

a. 0.0025 Hz

b. 7.51014 Hz

c. 3.0108 m/s

d. 700 nm

e. 400 nm

ANS: B PTS: 1

Which of the following features of a telescope determines its light-gathering power?

a. b. c. d. the focal length of the objective

the focal length of the eyepiece

the diameter of the objective

tength of the telescope tube

e. none of the above

ANS: C PTS: 1

The objective of most radio telescopes is similar to the objective of a reflecting optical telescope in

that

a. b. c. d. e. they are both concave in shape.

they are both convex in shape.

they are typically the same size.

they are both made of metal.

they have nothing in common.

ANS: A PTS: 1

Blue light differs from red light in that

a. b. c. d. e. blue light has a higher energy than red light.

blue light has a lower energy than red light.

blue light has a shorter wavelength than red light.

blue light has a longer wavelength than red light.

More than one of the above.

ANS: E PTS: 1

What is the relationship between color and wavelength for light?

a. b. c. Wavelength increases from blue light to red light.

Wavelength decreases from blue light to red light.

All colors of light have the same wavelength.42. 43. 44. 45. 46. 47. d. Wavelength depends on intensity not color.

ANS: A PTS: 1

In which way does a photon of blue light NOT differ from a photon of red light?

a. energy

b. speed

c. wavelength

d. color

e. frequency

ANS: B PTS: 1

Which of the following sequences of electromagnetic radiation is correct in order of increasing

energy?

a. gamma rays, X-rays, infrared, radio

b. radio, microwave, gamma rays, UV

c. visible, UV, X-rays, gamma rays

d. visible, microwave, radio, infrared

e. infrared, visible, radio, X-rays

ANS: C PTS: 1

The main reason for building large optical telescopes on Earth’s surface is

a. b. c. that there is a lot of money in science that needs to get spent.

to collect as much light as possible from faint objects.

to nullify the blurring effects of the Earth’s atmosphere and thus produce higher resolution

images.

d. e. to bring astronomical objects closer to make them brighter.

that the warm temperatures of the Earth’s surface allow for easier telescope operation.

ANS: B PTS: 1

What statement below best describes the refraction of light?

a. b. c. d. The absorption of light as it travels through a dense, transparent material.

The spreading out of white light according to wavelength.

The change in direction of a light ray as it passes to a medium of different optical density.

The change in direction of a ray of light as it reflects off a surface.

ANS: C PTS: 1

The light-gathering power of a telescope is directly proportional to

a. b. c. d. e. the diameter of the primary mirror or lens.

the focal length of the primary mirror or lens.

the ratio of the focal lengths of its primary mirror or lens and its eyepiece.

the length of the telescope tube.

the diameter of the eyepiece.

ANS: A PTS: 1

Chromatic aberration occurs in a ____ telescope when ____.

a. b. c. d. reflecting; different colors of light do not focus at the same point

refracting; different colors of light do not focus at the same point

reflecting; light of different wavelengths get absorbed by the mirror

refracting; light of different wavelengths get absorbed by the lens48. 49. 50. 51. 52. 53. ANS: B PTS: 1

The main reason for positioning many radio telescopes across a large area and combining the signals is

a. b. c. d. e. to observe more objects in a shorter amount of time.

provide a backup system if one or more of the telescopes go down.

to produce higher resolution images.

to avoid interference between signals from the separate telescopes.

to account for the motion of objects in the sky as a result of the Earth’s rotation.

ANS: C PTS: 1

Radio telescopes which use dishes to gather radio waves are ____ telescopes.

a. reflecting

b. refracting

c. deflecting

d. compound

e. retracting

ANS: A PTS: 1

A telescope whose objective is a lens and contains no mirrors is a(n) ____ telescope.

a. refracting

b. reflecting

c. deflecting

d. compound

e. retracting

ANS: A PTS: 1

In a reflecting telescope the objective is a ____.

a. prism

b. mirror

c. lens

d. diffraction grating

e. photographic plate

ANS: B PTS: 1

Which has the larger light-gathering power?

a. b. c. d. e. a telescope of 5 cm diameter and focal length of 50 cm

a telescope of 6 cm diameter and focal length of 100 cm

a telescope of 2 cm diameter and focal length of 100 cm

a telescope of 3 cm diameter and focal length of 75 cm

both b and c since they have the same focal length.

ANS: B PTS: 1

The resolving power of a telescope is

a. b. c. d. e. a measure of the minimum angular separation that can be seen with the telescope.

a measure of the maximum angular separation that can be seen with the telescope.

a measure of the amount of light that the telescope can gather in one second.

the separation between the objective and the image.

a measure of how blurry object appear in the telescope.

ANS: A PTS: 154. The largest single-dish radio telescope is

a. suspended on cables in a valley.

b. buried deep in a mine underground.

c. orbiting in space.

d. suspended from balloons in the upper atmosphere.

55. 56. 57. 58. 59. 60. ANS: A PTS: 1

What is the wavelength of the shortest wavelength light visible to the human eye?

a. 400 nm

b. 4000 nm

c. 7000 nm

d. 700 nm

e. 3108 m

ANS: A PTS: 1

Violet light has a wavelength of approximately ____.

a. 400 nm

b. 4000 nm

c. 7000 nm

d. 700 nm

e. 3108 m

ANS: A PTS: 1

There are ____ nanometers in one meter.

a. 1103

b. 1103

c. 1109

d. 1109

e. 400

ANS: D PTS: 1

The technique called ____ uses a high-speed computer to monitor atmospheric distortion and adjust

the optics of a telescope to partially compensate for the seeing.

a. photometry

b. chromatic aberration

c. active optics

d. spherical aberration

e. adaptive optics

ANS: E PTS: 1

A telescope that suffers from chromatic aberration and has a low light-gathering power is most likely

a. b. c. d. a small-diameter objective reflecting telescope.

a small-diameter objective refracting telescope.

a large-diameter objective refracting telescope.

a large-diameter objective reflecting telescope.

e. the Hubble Space Telescope.

ANS: B PTS: 1

What is the ratio of the light-gathering power of a 5-m telescope to that of a 0.5-m telescope?

a. 10b. 0.1

c. 0.01

d. 100

e. 25

ANS: D PTS: 1

61. CCD stands for a

a. photometer.

b. charge-coupled device.

c. spectrograph.

d. core collapse device.

e. grating.

62. 63. 64. 65. 66. ANS: B PTS: 1

A ____ is used to produce and analyze a spectrum.

a. photo

b. spectrograph

c. photometer

d. charge-coupled device

ANS: B PTS: 1

Observations of radio waves from astronomical objects suffer from poorer resolution than visible

observations with the same size dish (or mirror) because

a. b. c. d. e. the signals are so weak in the radio region.

the wavelength of radio waves is much longer than the wavelengths of visible light.

radio telescopes are generally much smaller in diameter than optical telescopes.

it is very difficult to detect radio waves.

radio telescopes don’t use solid mirrors.

ANS: B PTS: 1

In modern astronomy, an interferometer

a. b. c. d. e. is the highest resolution optical telescope ever built.

is located in Arecibo, Puerto Rico.

is a set of optical telescopes linked together to provide very high resolution.

is a set of radio telescopes linked together to provide very high resolution.

Either answers c or d.

ANS: E PTS: 1

____ penetrate(s) the Earth’s atmosphere to reach its surface.

a. X-rays

b. Radio waves

c. Visible light

d. Answers a and b

e. Answers b and c

ANS: E PTS: 1

The Hubble Space Telescope objective mirror is not affected by

a. bad seeing.

b. chromatic aberration.

c. diffraction.67. 68. 69. 70. 71. 72. d. Answers b and c

e. Answers a and b

ANS: E PTS: 1

Infrared space telescopes must have their mirror cooled to very low temperatures because otherwise it

would thermally emit too much ____ itself.

a. infrared radiation

b. radio waves

c. X-rays

d. gamma rays

e. all of the above

ANS: A PTS: 1

What statement below best describes the behavior of light encountering the objective lens of a

refracting telescope?

a. b. c. All light is absorbed as it travels though a dense, transparent material.

White light from astronomical objects is emitted by the lens.

Light rays are focused to form an image after they pass through the lens which is of

different optical density.

d. Light rays are focused to form an image after they reflect off the lens.

ANS: C PTS: 1

Which of the items below is electromagnetic radiation?

a. gamma rays

b. X-rays

c. visible light

d. radio

e. all of the above

ANS: E PTS: 1

Which of the waves below has the shortest wavelength?

a. gamma rays

b. X-rays

c. visible light

d. infrared

e. radio

ANS: A PTS: 1

An ordinary glass lens forms an image by ____________ of light.

a. reflection

b. refraction

c. diffraction

ANS: B PTS: 1

A convex lens is located at “B” and a light sources between “D” and “C”. light source form in the sketch?

Where will an image of thea. A

b. B

c. C

d. D

ANS: A PTS: 1

73. Compared to a smaller-objective lens, a larger-objective lens makes a star’s image

a. brighter.

b. dimmer.

c. no effect.

ANS: A PTS: 1

74. Which blurs our Earth-based view of celestial objects?

a. the sun

b. the moon

c. Earth’s atmosphere

ANS: C PTS: 1

75. A larger-objective lens shows ____________ a smaller-objective lens.

a. more detail than

b. less detail than

c. the same amount of detail as

ANS: A PTS: 1

76. Reflecting telescope objectives here on Earth do not have a problem with

a. “seeing”.

b. diffraction.

c. color fringes on the image.

d. all of the above.

ANS: C PTS: 1

COMPLETION

1. A(n) ____________________ telescope has an objective that is a lens.

ANS: refracting

PTS: 1

2. Refracting telescopes suffer from ____________________ aberration.

ANS: chromatic

PTS: 13. 4. 5. 6. 7. 8. 9. 10. The diagram below illustrates the layout and light path of a reflecting telescope of the

____________________ design.

ANS: Cassegrain

PTS: 1

A(n) ____________________ is used to measure the brightness and color of stars.

ANS: photometer

PTS: 1

A wave on a lake is found to have a wavelength of 2 m and a frequency of 0.3 Hz. What is the speed of

this wave?

ANS: 0.6 m/s

PTS: 1

The ____________________ is a measure of the finest detail that can be seen in an image.

ANS: resolution

PTS: 1

The ____________________ of a telescope is determined by the size of the objective.

ANS: light-gathering power

PTS: 1

The main lens or mirror of a telescope is called the ____________________.

ANS: objective

PTS: 1

A(n) ____________________ uses a mirror as its objective.

ANS: reflecting telescope

PTS: 1

The ____________________ is a measure of the clarity of the atmosphere.

ANS: seeingPTS: 1

11. The ____________________ is a measure of how many times larger the angular size of an object

appears through a telescope.

ANS: magnification

PTS: 1

12. The process of combining signals from separate telescopes to improve resolution is called

____________________.

ANS: interferometry

PTS: 1

13. A telescope that is 1.0 meter in diameter has a focal length of 10 meters. An eyepiece with a focal

length of 0.01 meters that is used with this telescope would have a magnification of

____________________?

ANS: 1000

PTS: 1

TRUE/FALSE

1. 300-nm light has a lower frequency than 500-nm light.

ANS: F PTS: 1

2. The largest optical telescope ever constructed was a refracting telescope.

ANS: F PTS: 1

3. X-rays easily penetrate Earth’s atmosphere and reach the ground from space.

ANS: F PTS: 1

4. Light can behave as a particle or as a wave.

ANS: T PTS: 1

5. The amount of energy a photon carries depends on its wavelength.

ANS: T PTS: 1

6. Reflecting telescopes are no longer popular with astronomers because they are expensive and suffer

from chromatic aberration.

ANS: F PTS: 1

7. The sidereal drive on a telescope mounting must turn the telescope eastward about the polar axis.ANS: F PTS: 1

8. One of the advantages of charge-coupled devices over photographic plates is that a CCD can record

bright and faint objects on the same exposure.

ANS: T PTS: 1

9. Telescopes observing in the far ultraviolet can work from high-flying aircraft.

ANS: F PTS: 1

10. Interferometry is easiest to use with telescopes that observe at very short wavelengths.

ANS: F PTS: 1

11. In a reflecting telescope, the objective is a mirror.

ANS: T PTS: 1

12. All radio telescopes are refracting telescopes.

ANS: F PTS: 1

13. The light-gathering power of a telescope increases as the size of the objective increases.

ANS: T PTS: 1

ESSAY

1. How do atmospheric windows limit observations made from Earth’s surface?

ANS:

Answer not provided.

PTS: 1

2. Why are nearly all recently built astronomical telescopes reflectors instead of refractors?

ANS:

Answer not provided.

PTS: 1

3. What causes chromatic aberration? Why does it not occur in reflecting telescopes?

ANS:

Answer not provided.

PTS: 1

4. What advantages does a large-diameter astronomical telescope have over a telescope of a smaller

diameter?5. 6. 7. 8. 9. 10. 11. ANS:

Answer not provided.

PTS: 1

How do electronic cameras resemble photographic plates? How do they differ?

ANS:

Answer not provided.

PTS: 1

Why were telescopes with very large, thin mirrors not built 50 years ago?

ANS:

Answer not provided.

PTS: 1

Why might astronomers someday establish an observatory on the moon? Why would radio

astronomers prefer the far side of the moon for their observatory?

ANS:

Answer not provided.

PTS: 1

How does the nature of radio waves allow a radio telescope to use a wire mesh surface? Would you

expect millimeter wavelength telescopes to need smoother surfaces than typical radio dishes? Why or

why not?

ANS:

Answer not provided.

PTS: 1

Why can infrared telescopes operate from high flying aircraft and high mountain tops whereas X-ray

telescopes must be placed in orbit?

ANS:

Answer not provided.

PTS: 1

Why must telescopes that observe in the far infrared be cooled?

ANS:

Answer not provided.

PTS: 1

List the advantages the Hubble Space Telescope has over ground-based telescopes.ANS:

Answer not provided.

PTS: 1

12. If the magnification of a telescope can be changed simply by exchanging eyepieces, why can’t you just

magnify objects to very large sizes by choosing an appropriate eyepiece?

ANS:

Answer not provided.

PTS: 1

13. Explain why the majority of large modern telescopes are not refractors.

ANS:

Answer not provided.

PTS: 1

14. Explain how interferometry works.

ANS:

Answer not provided.

PTS: 1

15. What are sources of light pollution and how do those affect astronomical observations?

ANS:

Answer not provided.

PTS: 1

16. What are some new techniques and technologies that enable construction of optical telescopes with

very large mirrors?

ANS:

Answer not provided.

PTS: 1

17. The figure below shows a single lens with two rays of white light incident on it from the left. Sketch

the paths of the blue, yellow, and red components of each of these rays to the point where the light

from the upper and lower rays would meet.ANS:

The blue rays should come to a focus closest to the right side of the lens, the red rays should come to a

focus furthest from the right side of the lens, and the focus of the yellow rays should be between the

red and blue focal points.

PTS: 1