Question 1

The amount of diffraction a telescope creates depends upon:

Accepted Answer

A)  whether the telescope is a refractor or a reflector. 
B)  the wavelength and the diameter of the telescope objective. 
C)  the magnification of the eyepiece. 
D)  the types of glass used in the achromat. 
E)  the transparency of the atmosphere. 
A)  whether the telescope is a refractor or a reflector. 
B)  the wavelength and the diameter of the telescope objective. 
C)  the magnification of the eyepiece. 
D)  the types of glass used in the achromat. 
E)  the transparency of the atmosphere. B

Question 2

Why is a complete image formed even if half of a lens or mirror is blocked?

Accepted Answer

While the image formed is only half as bright,each part of the objective "sees" and images the entire object.

Question 3

Explain why the image seen in astronomical telescopes is inverted.

Accepted Answer

In both reflectors and refractors,the eyepiece must be located behind the prime focus,so the light reaching it has "flipped over" in passing through the focus.

Question 4

What is true of radio telescopes?

Accepted Answer

A)  They have poorer angular resolution than a refractor. 
B)  They have better angular resolution than a reflector. 
C)  They are the smallest, most compact telescopes. 
D)  They can only be used above the atmosphere. 
E)  They are most sensitive to the opacity of the ozone layer. 
A)  They have poorer angular resolution than a refractor. 
B)  They have better angular resolution than a reflector. 
C)  They are the smallest, most compact telescopes. 
D)  They can only be used above the atmosphere. 
E)  They are most sensitive to the opacity of the ozone layer.

Question 5

The convex secondary mirror in this design focuses light down through a hole cut in the concave primary mirror.

Accepted Answer

A)  refractor 
B)  prime focus reflector 
C)  Newtonian reflector 
D)  Cassegrain reflector 
E)  interferometer 
A)  refractor 
B)  prime focus reflector 
C)  Newtonian reflector 
D)  Cassegrain reflector 
E)  interferometer

Question 6

A major advantage of a Newtonian reflector over a refractor is:

Accepted Answer

A)  its compact size. 
B)  the elimination of chromatic aberration. 
C)  there are only two lenses to grind. 
D)  the central hole in the mirror is smaller. 
E)  the elimination of the secondary mirror. 
A)  its compact size. 
B)  the elimination of chromatic aberration. 
C)  there are only two lenses to grind. 
D)  the central hole in the mirror is smaller. 
E)  the elimination of the secondary mirror.

Question 7

Why doesn't the Hubble Space Telescope need adaptive optics?

Accepted Answer

Adaptive optics correct poor s

Question 8

In astronomy,an interferometer can be used to:

Accepted Answer

A)  yield better seeing conditions with optical telescopes. 
B)  decrease the effects of light pollution in getting darker sky backgrounds. 
C)  improve the angular resolution of radio telescopes. 
D)  increase the sensitivity of infrared telescopes to longer wavelengths. 
E)  speed up the processing of CCD images. 
A)  yield better seeing conditions with optical telescopes. 
B)  decrease the effects of light pollution in getting darker sky backgrounds. 
C)  improve the angular resolution of radio telescopes. 
D)  increase the sensitivity of infrared telescopes to longer wavelengths. 
E)  speed up the processing of CCD images.

Question 9

Optical telescopes are usually used only at night,but radio telescopes can be used day or night.

Accepted Answer

A) True 
 B)False

Question 10

Refractor telescopes suffer from this separation of light into its component colors.

Accepted Answer

A)  limited diffraction 
B)  spherical aberration 
C)  chromatic aberration 
D)  bad seeing 
E)  refraction 
A)  limited diffraction 
B)  spherical aberration 
C)  chromatic aberration 
D)  bad seeing 
E)  refraction

Question 11

Based on their optical design,would an airline rather you bring your 8" Newtonian or Cassegrain to the next eclipse? Why?

Accepted Answer

Considering the restrictions o

Question 12

What is a CCD,and how does it work? Why is it replacing film?

Accepted Answer

A charge coupled device consists of a gr

Question 13

What type of telescope is the Hubble Space Telescope?

Accepted Answer

A)  refractor 
B)  prime focus 
C)  Newtonian 
D)  Cassegrain 
E)  Nasmyth/Coude 
A)  refractor 
B)  prime focus 
C)  Newtonian 
D)  Cassegrain 
E)  Nasmyth/Coude

Question 14

Green light has a shorter wavelength than orange light.In a 5-inch telescope,green light will:

Accepted Answer

A)  provide better angular resolution than orange light. 
B)  come to the same exact focus as orange light. 
C)  provide worse angular resolution than orange light. 
D)  allow dimmer stars to be observed. 
E)  reduce the effects of atmospheric turbulence. 
A)  provide better angular resolution than orange light. 
B)  come to the same exact focus as orange light. 
C)  provide worse angular resolution than orange light. 
D)  allow dimmer stars to be observed. 
E)  reduce the effects of atmospheric turbulence.

Question 15

Why do stars appear to twinkle?

Accepted Answer

In space,the light of the stars appears

Question 16

Galaxies look the same whether viewed in visible or X-ray wavelengths.

Accepted Answer

A) True 
 B)False

Question 17

Why is the image seen in astronomical telescope eyepieces inverted?

Accepted Answer

As the eyepiece must lie behin

Question 18

Which of the following greatly improves the angular resolution of radio maps?

Accepted Answer

A)  Schmidt corrector plates 
B)  more sensitive spectrometers 
C)  switching from film to CCD imaging 
D)  use of interferometers 
E)  chilling the infrared detectors 
A)  Schmidt corrector plates 
B)  more sensitive spectrometers 
C)  switching from film to CCD imaging 
D)  use of interferometers 
E)  chilling the infrared detectors

Question 19

The detectors on the Spitzer Space Telescope were cooled to near absolute zero in order to:

Accepted Answer

A)  allow the electronics in these instruments to operate most efficiently. 
B)  keep the telescope more nearly stationary. 
C)  prevent the infrared radiation from the instruments interfering with the infrared signals from space. 
D)  improve the angular resolution of the telescope. 
A)  allow the electronics in these instruments to operate most efficiently. 
B)  keep the telescope more nearly stationary. 
C)  prevent the infrared radiation from the instruments interfering with the infrared signals from space. 
D)  improve the angular resolution of the telescope.

Question 20

What is the primary purpose of an astronomical telescope?

Accepted Answer

A)  to magnify and make distant objects appear closer 
B)  to separate light into its component colors 
C)  to measure the intensity of light very accurately 
D)  to access wavelengths that we cannot see visually 
E)  to collect a lot of light and bring it to a focus 
A)  to magnify and make distant objects appear closer 
B)  to separate light into its component colors 
C)  to measure the intensity of light very accurately 
D)  to access wavelengths that we cannot see visually 
E)  to collect a lot of light and bring it to a focus

Exam 5: Telescopes: The Tools of Astronomy

The amount of diffraction a telescope creates depends upon:

Why is a complete image formed even if half of a lens or mirror is blocked?

Explain why the image seen in astronomical telescopes is inverted.

What is true of radio telescopes?

The convex secondary mirror in this design focuses light down through a hole cut in the concave primary mirror.

A major advantage of a Newtonian reflector over a refractor is:

Why doesn't the Hubble Space Telescope need adaptive optics?

In astronomy,an interferometer can be used to:

Optical telescopes are usually used only at night,but radio telescopes can be used day or night.

Refractor telescopes suffer from this separation of light into its component colors.

Based on their optical design,would an airline rather you bring your 8" Newtonian or Cassegrain to the next eclipse? Why?

What is a CCD,and how does it work? Why is it replacing film?

What type of telescope is the Hubble Space Telescope?

Green light has a shorter wavelength than orange light.In a 5-inch telescope,green light will:

Why do stars appear to twinkle?

Galaxies look the same whether viewed in visible or X-ray wavelengths.

Why is the image seen in astronomical telescope eyepieces inverted?

Which of the following greatly improves the angular resolution of radio maps?

The detectors on the Spitzer Space Telescope were cooled to near absolute zero in order to:

What is the primary purpose of an astronomical telescope?

Charting the Heavens: The Foundations of Astronomy

The Copernican Revolution: The Birth of Modern Science

Radiation: Information from the Cosmos

Spectroscopy: The Inner Workings of Atoms

The Solar System: Comparative Planetology and Formation Models

Earth: Our Home in Space

The Moon and Mercury: Scorched and Battered Worlds

Venus: Earth's Sister Planet

Mars: A Near Miss for Life?

Jupiter: Giant of the Solar System

Saturn: Spectacular Rings and Mysterious Moons

Uranus and Neptune: The Outer Worlds of the Solar System

Solar System Debris: Keys to Our Origin

Exoplanets: Planetary Systems Beyond Our Own

The Sun: Our Parent Star

The Stars: Giants,Dwarfs,and the Main Sequence

The Interstellar Medium: Gas and Dust among the Stars

Star Formation: A Traumatic Birth

Stellar Evolution: The Life and Death of a Star

Stellar Explosions: Novae,Supernovae,and the Formation of the Elements

Neutron Stars and Black Holes: Strange States of Matter

The Milky Way Galaxy: A Spiral in Space

Galaxies: Building Blocks of the Universe

Galaxies and Dark Matter: The Large-Scale Structure of the Cosmos

Cosmology: The Big Bang and the Fate of the Universe

The Early Universe: Toward the Beginning of Time

Life in the Universe: Are We Alone?

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