Download Quiz Lecture 6

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TAKEN FROM HORIZONS 7TH EDITION CHAPTER 5 TUTORIAL QUIZ
-----------------------------------------------------------------------1.
Poor "seeing" refers to
a. the problem of finding the star of interest out of the millions
visible through telescopes.
b. buildings and other obstructions near the observatory.
c. the blurring of an image by movements of air in the atmosphere.
d. clouds.
answer: c
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Radio telescopes are built large because
a. radio waves have very poor resolution, and resolution improves with
size of telescope.
b. radio waves are very weak, and a large telescope can collect more
than a small one.
c. radio waves are very long, and therefore require something large to
"catch" them.
d. all of these choices.
answer: d
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X-ray telescopes are important to modern astronomers because they can
detect the presence of
a. violent events such as matter colliding with neutron stars.
b. cool clouds of hydrogen drifting between the stars.
c. gas clouds forming into stars.
d. features inside of planets, such as volcanoes.
answer: a
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Which of the following is NOT a modern addition to astronomy that allows
for a better understanding of the nature of celestial objects?
a. Satellites carry telescopes above Earth's atmosphere to collect
radiation that is absorbed by the atmosphere.
b. CCD's replace the use of the human eyeball.
c. Multiple-mirror telescopes overcome the effects of gravity on large
mirrors.
d. Telescopes have been placed on the backside of the Moon to avoid
interference from radiation originating on Earth.
answer: d
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Since telescopes tuned to different wavelengths reveal different
pictures of the sky, our interest in sending up the Space Infrared
Telescope Facility satellite is that it will reveal the location of
a. supernova remnants.
b. "birthing" or forming stars.
c. hot gas clouds.
d. neutron stars.
answer: b
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In general, the primary function of a telescope is to
a. separate out one type of radiation from another.
b. act as a "light bucket" to catch photons.
c. measure the amount of radiation produced inside of an object in space.
d. measure the wavelengths of the incoming types of radiation.
answer: b
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Cool objects in space are detected by using
a. radio telescopes.
b. X-ray telescopes.
c. spectrographs.
d. CCD's.
answer: a
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Which of the following is NOT a reason for building telescopes atop
mountains?
a. Astronomical objects are closer from atop a mountain, and therefore
appear brighter.
b. Since the air is thinner there, the sky is darker and astronomical
objects appear brighter.
c. Air turbulence is less from atop a mountain, so seeing conditions are better.
d. Mountains are generally located away from sources of light pollution.
answer: a
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If the diameter of the objective mirror of a reflecting telescope is
tripled, its light-gathering power
a. none of these choices. Light-gathering power is determined by focal
length.
b. increases by a factor of 3.
c. increases by a factor of 9.
d. increases by a factor of 6.
answer: c
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If you wished to send pulses of electromagnetic energy from Earth's
surface out into space in order to contact ET's, your chances of success
are greatest if you send
a. X-rays or gamma rays.
b. infrared, ultraviolet, or visible waves.
c. visible or radio waves.
d. visible waves only.
answer: c
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Often times, two or more radio telescopes are linked together
electronically while studying the same object. This is primarily
for the purpose of
a. allowing astronomers from different countries to share in the
excitement of new discoveries.
b. increasing the focal length of the telescope, and thereby increasing
the magnification.
c. verifying that the main telescope is tracking the correct object.
d. improving the resolution of the object being studied.
answer: d
-----------------------------------------------------------------------12.
In order to "track" objects accurately, the axis around which a
telescope rotates must point exactly toward
a. an altitude angle equal to 90 degrees minus the latitude of the
telescope.
b. one of the celestial poles.
c. an altitude angle equal to 90 degrees plus the latitude of the
telescope.
d. the star Polaris.
answer: b
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CCDs are replacing photographic plates in telescopes because
a. photographic plates do not hold up under the cold temperatures on
mountaintops.
b. they do not require as long an exposure time for the same brightness of image.
c. CCDs are less expensive to produce.
d. they are sensitive to types of radiation that photographic plates are not.
answer: b
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Generally speaking, the function of an astronomical observatory is to
a. produce images of objects that are as large and magnified as possible.
b. gather and analyze radiation from space.
c. provide the public with the opportunity to know what is in space
besides Earth.
d. discover as many new objects in space as possible.
answer: b
-----------------------------------------------------------------------15.
Why do modern astronomers prefer reflecting over refracting telescopes?
a. For a given collecting power, the diameter of an objective mirror is
smaller than the diameter of an objective lens, and therefore less
expensive.
b. High-quality glass is not needed in a reflecting telescope, since
light does not reflect off the glass.
c. None of these choices. They prefer refracting over reflecting.
d. Spectrographs can be attached to reflecting telescopes but not to
refracting telescopes.
answer: b
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16.
Different types of radiation are referred to by
a. frequency.
b. wavelength.
c. any of these choices.
d. adopted names (X-rays, visible, etc.).
answer: c
-----------------------------------------------------------------------17.
If you are shopping for a telescope, what feature most closely
associated with performance would be your first consideration?
a. The degree of magnification it is capable of.
b. The number of eyepieces that come with the telescope.
c. The diameter of the objective or mirror.
d. The focal length.
answer: c
-----------------------------------------------------------------------18.
Since radio waves are inherently long in wavelength,
a. their ability to resolve small detail in astronomical objects is weak.
b. they are easily detected by the human ear.
c. they travel slower than other types of radiation.
d. large telescopes are not required to detect them.
answer: a
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The largest radio telescope in the world is
a. of the refracting type.
b. located at Mauna Kea, Hawaii.
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c. located in Arecibo, Puerto Rico.
d. called the Hubble Space Telescope.
answer: c
-----------------------------------------------------------------------20.
The largest optical telescopes in the world are reflecting telescopes
because
a. None of these choices. The largest optical telescopes are of the
refracting type.
b. the degrading effects of gravity are easier to overcome in reflecting telescopes.
c. spectrographs can be attached to reflecting telescopes but not to
refracting telescopes.
d. "seeing" conditions are less of a concern for reflecting telescopes.
answer: b
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