Download Quiz # 2

Introductory Astronomy
Fall 2002
Quiz # 2
Name______________________________
1. In the geocentric model of the solar system developed by Ptolemy,
A) planets move with varying speeds in elliptical orbits around the Earth.
B) planets move at constant speeds in circular orbits around the Earth.
C) planets move in circular epicycles around the Sun while the Sun moves in a circular orbit
around the Earth.
D) planets move in circular epicycles while the centers of the epicycles move in circular orbits
around the Earth.
2. Which of the following statements CORRECTLY describes why Copernicus decided that the orbits
of Mercury and Venus are smaller than the orbit of the Earth?
A) Both planets can sometimes be seen high in our sky at midnight.
B) Both planets show a complete cycle of phases, like the Moon.
C) Both planets stay fairly close to the Sun in our sky.
D) Both planets occasionally pass through conjunction with the Sun, as seen from the Earth.
3. When Saturn is at its closest distance from the Earth, it is at
A) greatest elongation (about 47 degrees from the Sun).
B) opposition.
C) conjunction.
D) inferior conjunction.
4. According to Kirchhoff's Laws, the continuous spectrum of light from a hot star, after passing
through a cool gas cloud,
A) will be enhanced at infrared wavelengths by a continuous spectrum emitted by the cool gas.
B) will contain additional emission lines from energy emitted by the atoms of the cool gas.
C) will show absorption features where light has been absorbed by the atoms of the cool gas.
D) will be unaffected, because atoms in the gas cloud are too cool to absorb or emit energy.
5. The New Zealand physicist, Lord Rutherford, and his colleagues in England demonstrated the
existence of the very small but massive nucleus inside every atom in which crucial experiment?
A) The deflection, and occasional reflection backward, of energetic nuclear particles from a beam
aimed at a thin metal sheet.
B) Measurement of the spectrum of light emitted from a thin, heated metal sheet.
C) The detection of the motion of electrons around the nucleus by the use of a very powerful
microscope.
D) The emission of electrons from a metal surface illuminated with UV light.
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Bonus. The spectrum of a star shows an equivalent set of dark absorption lines to those of the Sun, but
with one exception. Every line appears at a slightly longer wavelength, shifted toward the red end
of the spectrum. What conclusion can be drawn from this observation?
A) A cloud of cold gas and dust surrounds the star and is absorbing light from it.
B) The star is moving rapidly toward the Earth.
C) The temperature of the star's surface is higher than that of the Sun.
D) The star is moving rapidly away from Earth.
I pledge that I have neither given nor received any unauthorized aid on this assignment.
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Answer Key
1.
2.
3.
4.
5.
Bonus.
D
C
B
B
C
D
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