Download Chapter Six: Astronomical Tools

Chapter Six: Astronomical Tools
1) The visible part of the electromagnetic spectrum can be divided into seven color bands of Red,
Orange, Yellow, Green, Blue, Indigo and Violet (from long to short wavelength). A single
photon of which of these colors has the greatest amount of energy?
a. red
b. orange
c. green
d. blue
e. violet
2) The entire electromagnetic spectrum can be divided into the seven bands of radio, microwave,
infrared, visible, ultraviolet, x-ray and gamma-ray (from longest to shortest wavelength). To
which of these two bands is Earth’s atmosphere the most transparent?
a. x-ray and gamma
b. ultraviolet and infrared
c. visible and ultraviolet
d. microwave and radio
e. visible and radio
3) In which device is chromatic aberration a problem for astronomers?
a. the primary mirrors of reflecting telescopes
b. the primary lenses of refracting telescopes
c. the prism
d. both a and b above
e. all of the above
4) Why have no large refracting telescopes been built in the years since 1900?
a. refracting telescopes suffer from chromatic aberration
b. making large glass lenses without interior defects is difficult
c. refracting telescopes have several surfaces to shape and polish
d. large glass lenses are more difficult to support than large mirrors
e. all of the above
5) Which power of a telescope is the least important?
a. light gathering power
b. resolving power
c. magnifying power
d. both a and b above
d. both a and c above
6) Which power of an optical telescope is determined by the primary mirror or lense?
a. light gathering power
b. resolving power
c. magnifying power
d. both a and b above
e. both a and c above
7) Which power of a large ground-based optical telescope is severly limited by Earth’s
atmosphere on a cloudless night?
a. light gathering power
b. resolving power
c. magnifying power
d. both a and b above
e. both a and c above
8) Adaptive optics enables Astronomers to
a. resolve more detail of astronomical objects
b. account for problems with “seeing”
c. use their eye glasses when looking through an eyepiece
d. both a and b above
e. none of the above
9) What can radio telescopes do that optical telescopes cannot?
a. find the location of cool hydrogen gas
b. see through dust clouds
c. detect high temperature objects
d. both a and b above
e. all of the above
10) The 300-m telescope in Arecibo, Puerto Rico is
a. used for ultraviolet astronomy
b. used for infrared astronomy
c. used for radio astronomy
d. used for gamma ray astronomy
e. observes all of the above
11) Why are near-infrared telescopes located on mountaintops and ultraviolet telescopes located
in Earth orbit?
a. the primary infrared blocker, water vapor, is mostly in the lower atmosphere
b. the primary ultraviolet blocker, ozone, is located high in the atmosphere, far above
mountaintops
c. ultraviolet telescopes require the low temperature of space to operate
d. both a and b above
e. both a and c above
12) Why must far-infrared telescopes be cooled to a low temperature?
a. to reduce interfering heat radiation emitted by the telescope
b. to protect the sensitive electronic amplifiers from overheating by sunlight
c. to improve their poor resolving power
d. to improve their poor magnifying power
e. to make use of the vast supplies of helium stockpiled by the United States