Telescope: The Tools Of Astronomy Test Review

Question 1

What is the primary purpose of an astronomical telescope?

Answer 1

To collect a lot of light and bring to focus

Question 2

The process occurring when photons bounce off a polished surface is called:

Answer 2

Reflection

Question 3

Which design is subject to chromatic aberration?

Answer 3

Refractor

Question 4

The tendency of a wave to bend as it passes from one transparent medium to another is called:

Answer 4

Refraction

Question 5

The primary purpose of a telescope is to:

Answer 5

Collect a lot amount of light and bring it into focus

Question 6

What problem do refractor telescopes have that reflectors don’t?

Answer 6

Chromatic Aberration

Question 7

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

Answer 7

The elimination of chromatic aberration

Question 8

Why are most large telescopes reflectors not refractors?

Answer 8

• large lenses deform under their own weight but mirrors can be supported
• reflectors do not suffer chromatic aberration, but refractors do
• large mirrors need only one optical surface
• large very clear lenses are harder to cast

Question 9

Which design has a convex primary mirror and flat secondary mirror, with the eyepiece located on the top of the telescope tube?

Answer 9

Newtonian Reflector

Question 10

Which method of astronomical measurement is the precise measurement of brightness?

Answer 10

Photometry

Question 11

What is the resolution of a telescope?

Answer 11

It’s ability to distinguish two adjacent objects close together in the sky

Question 12

What are two advantages of large scopes over small ones?

Answer 12

Large telescopes has more light grasp and better resolution

Question 13

What type of telescope is the Hubble Space Telescope?

Answer 13

Cassegrain

Question 14

The most important advantage of CCDs over film is that:

Answer 14

They record much more light in a given exposure time

Question 15

A mountain top is an especially good site for infrared telescopes since:

Answer 15

• cold weather helps sensitivity of infrared cameras
• they are closer to celestial objects
• you are above most of the carbon dioxide and water vapor in the atmosphere
• less air above means better seeing in many cases

Question 16

What problem does adaptive optics correct?

Answer 16

Turbulence in the Earth’s atmosphere which creates twinkling

Question 17

Which of the following is a problem inherent in all large radio telescopes?

Answer 17

Radio waves have long wavelengths, radio telescopes have poor resolution

Question 18

Compared to optical telescopes, radio telescopes are built large because:

Answer 18

Radio photons don’t carry much energy

Question 19

Which of the following is currently supplying high resolution X-ray images from space?

Answer 19

Chandra

Question 20

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

Answer 20

Prevent the infrared radiation from the instruments interfering with the infrared signals from soace

Question 21

The action of lenses depends mainly on:

Answer 21

Changing the directions of light waves or rays

Question 22

A real image can be cast on a screen by:

Answer 22

converging lens; only a virtual image

Question 23

A diverging lens forms:

Answer 23

Only a virtual image

Question 24

Chromatic Aberrations are cause by:

Answer 24

Different colors of light traveling at different speeds

Question 25

The farther light is from a source:

Answer 25

The more spread out light becomes