PH109 Exploring the Universe, Spring 2002
Please indicate the best answer on the answer sheet provided.
1. Polaris, the North Star, does not appear to move in the sky because:
a. The stars are fixed relative to each other.
b. It lies approximately over the northern axis of the Earth.
c. It is too nearby for its motion to be discernible.
d. It is located directly overhead for everyone on Earth.
2. The vernal equinox occurs in the month of
a. December, b. March, c. June, d. August
3. The sun is highest (greatest declination) at the
a. vernal equinox, b. winter solstice, c. autumnal equinox, d. summer solstice
4. During the course of the night, a star's celestial coordinates:
a. increase, b. remain constant, c. decrease, d. none of the above
5. Viewed looking down upon the North Pole, the Earth would be seen rotating:
a. clockwise, b. counter-clockwise, c. neither, it doesn't rotate, d. north to south
6. The Earth's equator is tilted how much with respect to the plane of the ecliptic?
a. 0 degrees, b. 23 1/2 degrees, c. 45. Degrees, d. 66 1/2 degrees
7. If an object is moving toward you, what effect do you observe in the spectrum of that object?
a. It appears red-shifted, b. The light appears to be moving faster.
c. All the spectral lines appear broadened, d. It appears blue-shifted.
8. What problem are adaptive optics used to correct?
a. the opacity of the Earth's atmosphere
b. defects in the optics of the telescope
c. slight errors in the telescope's mount to compensate for the Earth's rotation
d. effects of atmospheric turbulence
9. For what is an interferometer used?
a. to decrease the effects of atmospheric seeing for optical telescopes
b. to decrease the effects of light pollution in the images
c. to increase the sensitivity of infrared telescopes
d. to improve the angular resolution of telescopes
10. All large modern telescopes are
a. refractors, b. Cassegrains, c. Reflectors, d. Coudes
11. A light year is
a) the characteristic size of light , b) the distance the Earth travels around the sun in one year
c) the distance light travels in one year, d) the time it takes light to travel around the Earth's orbit
12. The observed changing positions of the stars during a night is the result of the
a) tilt of the Earth's axis , b) rotation of the Earth on its axis
c) rotation of the stars on their axes, d) revolution of the Earth around the sun
13. Paris is about 1/4 of the way around Earth from Chicago. On a night when people in Chicago
see a first quarter moon, people in Paris see
a) a new moon, b) a first quarter moon, c) a full moon, d ) a third quarter moon
14. The phases of the moon are caused by
a) the moon moving in and out of Earth's shadow
b) different fractions of the moon being illuminated by the sun
c) different degrees of darkness on the moon
d) different amounts of the illuminated half of the moon being visible from Earth
15. The apparent path of the sun around the celestial sphere against the background of the stars
during the year is the
a) celestial meridian, b) ecliptic, c) sun's diurnal circle, d) celestial equator
16. In the absence of excitation, electrons in an atom tend to be
a) in any allowed orbit , b) in the lowest allowed orbit, c) in the nucleus, d) not in the atom at all
17. Star “a” appears bluish white in color, while star “b” appears reddish in color. This tells you that
a) star a is less luminous than star b, b) star a is hotter than star b,
c) star a is more luminous than star b, d) star a is cooler than star b
18. The line which divides the celestial sphere into northern and southern hemispheres is the
a) ecliptic, b) celestial equator, c) meridian, d) horizon
19. If the Earth were inclined more on its axis than it currently is, what would be the consequences?
a) more drastic seasons, b) a longer year, c) more global warming, d) no solstices or equinoxes
20. Given the equation FG = GMm/d2 , if two objects suddenly become separated by twice their distance, what happens to the gravitation force between them
a) stays the same, b) increases by a factor of four
c) decreases by a factor of four, d) decrease by a factor of two
21. Newton's second law of motion states F = Ma; where F equals the applied force, M is the mass, and a equals the acceleration. If I have two masses M1 and M2 and I apply the same force to both of them but M1 accelerates three times faster than M2. What can I say about M1 compared to M2?
a) M1 is three times more than M2, b) M1 is three times less than M2,
c) M1 is nine times more than M2, d) M1 is nine times less than M2
22. All wave phenomena are characterized by a wavelength, a frequency, and a velocity. They are related by the equation C = ln where C is the velocity of the wave, l is the wavelength, and n is the frequency. If I double the wavelength of a wave, what happens to the frequency
a) it stays the same, b) it increases by 2, c) it decreases by 2, d) it increases by 4
23. A planet in a highly elliptical orbit has its greatest speed when
a) it is closest to the Sun, b) when it is furthest from the Sun
c) when the Sun is on the equator, d) when the Sun is on the solstice
24. Why are there seven days of the week on our current calendars?
a) seven was the only number which was easily divided into the number of months of the year,
b) seven was considered a "magic" number,
c) that was how many celestial objects in the sky moved with respect to other objects,
d) the Roman kingdom of the time had seven regions
25. What do we call the event when the Moon's shadow falls on the Earth's surface
a) lunar eclipse, b) solar eclipse, c) evening solstice, d) shadow time
26. Why are there 12 months in a year on our current calendar?
a) the year is easily divisible into 12 parts, b) 12 was considered a "magic" number,
c) there are 12 lunar cycles in a year, d) because there are 12 Zodiac signs in the sky
27. I wake up in the middle of nowhere with amnesia. The only thing I can remember is my astronomy class. I notice at night that the north star appears to be 25 degrees above my northern horizon. What can I write on the note in the bottle I throw out to sea that will help my rescuers find me?
a) my longitude is 25 degrees, b) my latitude is 25 degrees,
c) my right ascension is 25 degrees, d) my declination is 25 degrees
28. Which constellation contains stars which "point" to the north star
a) Big Dipper, b) Orion, c) Little Dipper, d) Northern Cross
29. What kind of a telescope uses a magnifying lens in the front end to image distant objects?
a) reflecting, b) refracting, c) X-ray, d) Georgian
30. Local noon corresponds to the time when the Sun is at the
a) zenith, b) meridian, c) nadir, d) ecliptic
31. The point directly over an observer's head is that observer's
a) equator, b) pole, c) zenith, d) node
32. The sun moves
a. about one degree westward each day., b. about one degree eastward each day.
c. about 360 degrees westward each day., d. about 360 degrees eastward each day.
33. Galileo's observations of the gibbous phase of Venus proved
a. that Venus orbited the sun., b. that Earth orbited the sun.
c. that all of the planets orbited the sun., d. that the moon orbited Earth.
34. 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. As the train approaches, the horn will sound lower in pitch than when it is moving away.
b. As the train approaches, the horn will sound higher in pitch than when it is moving away.
c. There will be no change in the pitch of the horn as it moves by.
d. The horn will get louder as the train moves away from you.
35. Why were epicycles used in Ptolemy's model of the solar system?
a) to account for the parallaxes of stars
b) to compensate for the ellipticity of the orbits of the planets
c) to explain the retrograde motions of planets
d) to explain the phenomenon of day and night
36. Which one of Kepler's laws explains what happens when a twilling ice skater brings their arms towards their center?
a) the planets follow ellipses, b) P2 = a3,
c) equal areas in equal times, d) Fg=GMM/d2
37. A hypothetical planet orbits the Sun a distance of 3 AU. What is its orbital period if you know P2=a3, where P is the period and a is the semi-major axis?
a) 2.8 years, b) 3.0 years, c) 5.2 years, d) 9.0 years
38. A shift in the direction of an object caused by a change in the position of an observer is called
a) parallax, b) precession, c) the Coriolis effect, d) epicycle motion
39. Aliens abduct me but then set me down at a different place on the Earth (I think). I observe the diurnal motion of the stars and note that they rise straight up in the East go overhead and set straight in the West. Where am I?
a) North Pole, b) South Pole, c) Equator, d) Can’t Tell
40. What is the relative size of the Moon to the Earth?
a) 1/4 as big, b) 1/2 as big, c) 1/3 as big, d) 1/10 as big