Download Quiz # 3

Spring 2010
Quiz 3
UCGEN1750
Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
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1. An astronomer discovers a new star and wants to measure its temperature. She would do this by:
a. measuring how much light the star reflects
b. sending a graduate student with a very long (and durable) thermometer to the star's
vicinity
c. measuring the Doppler shift of its spectral lines
d. making a blackbody curve and finding the wavelength of the peak (maximum)
e. measuring the intensity of radio waves the star gives off
2. The most important function of an astronomical telescope is to:
a. pierce through the clouds so a cloudy night is not wasted
b. bring distant objects closer by pulling on the light
c. collect as much light as possible and bring it to a focus
d. enhance the colors of an object
e. magnify (enlarge) celestial objects so we can see them clearly
3. Why do different types of atoms (elements) give off or absorb different spectral lines?
a. in some elements, electrons can only move to odd numbered levels, in others only to even
numbered ones
b. in heavier elements, diffraction spreads out the lines that the atom produces, making the
colors different
c. because the spacing of the energy levels is different in different atoms
d. all elements have the same lines, but they are Doppler shifted by different amounts
e. because some atoms do not have a ground state, while others have three or four
4. If I were to scale up an atom until it were the size of a sports arena, the space filled by the positive charges
inside the atom (according to the work of Ernest Rutherford early in this century) would be:
a. this question cannot be answered (even roughly) without knowing which kind of atom we
are discussing
b. as big as the space filled by all the negative charges (that's why the atom is neutral)
c. very small (perhaps the size of a soccer ball) and in the middle
d. an extremely thin layer spread completely around the outer walls of the stadium
e. as big as the entire stadium (and very thinly spread out)
5. After a nice dinner around the campfire on a camping trip, you and a friend decide to get away from the fire to
observe the stars. As you get farther and farther away, you see the brightness of the fire:
a. decrease as the distance squared
b. change more and more in color (becoming redder)
c. remain the same
d. increase with distance
e. this can't be answered without having more information
6. Which of the following travels through space the fastest?
a. x-rays
b. infrared
c. radio waves
d. light
e. you can't fool me, all of these travel through space at the same speed
7. Astronomers observe a typical star using a telescope and a spectrometer. They will see:
a. a Doppler shift
b. an absorption spectrum
c. an emission spectrum
d. a continuous spectrum
e. more than one of the above
____ 8. The ____ of a telescope is a measure of its ability to show fine detail and depends on the diameter of the
objective.
a. light-gathering power
b. spherical aberration
c. focal length
d. magnifying power
e. resolving power
____ 9. The size of the device that gathers (collects) radiation is called a telescope's:
a. aperture
b. focal width
c. resolution
d. magnification
e. Galilean criterion
____ 10. You are standing near a railroad track and a train is moving toward you at 60 mph and blowing its horn. What
will you notice as the train moves past you?
a. The horn will get louder as the train moves away from you.
b. The horn will get quieter as the train moves toward you
c. There will be no change in the pitch of the horn as it moves by.
d. As the train approaches, the horn will sound lower in pitch than when it is moving away.
e. As the train approaches, the horn will sound higher in pitch than when it is moving away.
Spring 2010
Quiz 3
Answer Section
MULTIPLE CHOICE
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D
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C
A
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A
E
UCGEN1750