Introductory Astronomy - Quiz 3
Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
__C_ 1. The light which allows you to see this very interesting quiz is made up of waves. In these waves, the distance
between crests is called the:
a. frequency
b. velocity
c. wavelength
d. amplitude
e. you can't fool me; in these waves, the distance between crests is zero
__B_ 2. Which of the following has the highest frequency?
a. visible light
b. gamma rays
c. radio waves
d. ultraviolet
e. you can't fool me, all these have the same frequency
__C_ 3. 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. increase with distance
b. remain the same
c. decrease as the distance squared
d. change more and more in color (becoming redder)
e. this can't be answered without having more information
__E_ 4. Not all wavelengths of electromagnetic radiation can penetrate the Earth's atmosphere. Of the following types of
waves that come from space, which one are you likely to be able to detect most easily from our planet's surface:
a. x-rays
b. gamma rays
c. infrared waves
d. ultraviolet waves
e. radio waves of the wavelength that carry FM broadcasts
__B_ 5. (In the absence of a strong magnetic field), what is the chief factor that determines what type of electromagnetic
radiation objects give off:
a. their mass
b. their temperature
c. their overall motion
d. their chemical makeup
e. their size
__B_ 6. An astronomer discovers a new star and wants to measure its temperature. She would do this by:
a. measuring the Doppler shift of its spectral lines
b. making a blackbody curve and finding the wavelength of the peak (maximum)
c. measuring the intensity of radio waves the star gives off
d. measuring how much light the star reflects
e. sending a graduate student with a very long (and durable) thermometer to the star's
vicinity
__E_ 7. When white light passes from the air into a different medium such as glass, it:
a. is dispersed into different colors
b. is reflected backwards
c. is refracted (bent)
d. is Doppler shifted
e. more than one of the above
__C_ 8. 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. as big as the entire stadium (and very thinly spread out)
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 BB) and in the middle
d. an extremely thin layer spread completely around the outer walls of the stadium
e. this question cannot be answered (even roughly) without knowing which kind of atom we
are discussing
__D_ 9. Why do different types of atoms (elements) give off or absorb different spectral lines?
a. all elements have the same lines, but they are Doppler shifted by different amounts
b. in some elements, electrons can only move to odd numbered levels, in others only to even
numbered ones
c. in heavier elements, diffraction spreads out the lines that the atom produces, making the
colors different
d. because the spacing of the energy levels is different in different atoms
e. because some atoms do not have a ground state, while others have three or four
__C_ 10. How do astronomers learn what elements are present in a given star?
a. look at what color light dominates its continuous spectrum
b. listen for coded signals in the radio waves it gives off in the FM band
c. look at the absorption lines in its spectrum
d. send spacecraft like Voyager to examine its make-up from close-up
e. compare visible-light photographs of the star (taken with large telescopes) to those of the
Sun.
Introductory Astronomy - Quiz 3
Answer Section
MULTIPLE CHOICE
1. ANS: C
2. ANS: B
3. ANS: C
4. ANS: E
5. ANS: B
6. ANS: B
7. ANS: E
8. ANS: C
9. ANS: D
10. ANS: C