First Practice Exam

1) Eclipses of the Sun and the Moon do NOT occur every month because the

a) Earth's axis of rotation is inclined to its orbital plane.
b) Earth's orbit is not a circle.
c) Moon's orbit is not a circle.
d) Moon's orbit is tilted with respect to the Earth's orbit.
e) Moon's synodic period is longer than its orbital period.

2) An eclipse of the Moon occurs when the

a) Earth gets inside the shadow of the Moon.
b) Moon gets inside the shadow of the Earth.
c) Moon gets between the Earth and the Sun.
d) Moon reaches its NEW phase.
e) Moon reaches quadrature.

3) People see many more eclipses of the Moon than eclipses of the Sun in their lives. This occurs because

a) lunar eclipses occur far more often than solar eclipses.
b) lunar eclipses occur at night.
c) solar eclipses can occur only during the daytime.
d) one whole hemisphere of Earth views every lunar eclipse.
e) all of the above are reasons for this fact.

4) Of all the physical properties of the stars, the one that is most nearly the SAME for all stars is

a) luminosity.
b) radius.
c) chemical composition.
d) surface temperature.
e) mass.

5) Most of the stars in our galaxy are now on the main sequence of the H-R diagram. That is because

a) it is the only stable configuration for a star.
b) most of the stars are very young.
c) red giants only form from the most massive stars.
d) it is the longest lived phase of stellar evolution.
e) the galaxy is too young to have white dwarf stars.

Putting It All Together -- A Walk Under the Night Sky
You have learned much about the sky and the things that happen which can be seen. The real significance of any knowledge is the ability to apply it in reality. Imagine that you are walking with a friend just after the Sun has set, while a nearly full Moon is low in the southeastern sky (this is the case for tonight by the way!). Your friend asks:

6) You would then tell your friend that the different colors of stars are caused by

a) different chemicals present in the star's atmospheres.
b) Doppler shifts caused by their motions.
c) different surface temperatures.
d) different luminosities.
e) dust in space that absorbs light.

7) You would then show your friend an example of a cool star by pointing to one that is

a) bright.
b) blue.
c) orange.
d) dim.
e) twinkling rapidly.

8) ``Of all the stars we can see in the sky this moment, which is the largest one?'' your friend asks. You search the sky and then point to one that is

a) bright and blue.
b) bright and red.
c) twinkling very rapidly.
d) brighter than all other stars.
e) moving faster than all other stars.

9) Your friend asks if you know what the stars are made of, and you reply that they are all made mostly of

a) carbon and oxygen.
b) hydrogen and oxygen.
c) carbon and nitrogen.
d) hydrogen and helium.
e) fire.

10) ``Are the brightest stars the nearest ones to us?'' your friend asks, and you say they are not necessarily close because

a) brightness of stars does not depend upon distance.
b) big stars must always appear brighter than small stars.
c) bright stars have much more hydrogen than dim stars.
d) some are binary stars that emit twice as much light.
e) even a distant star may look bright to us if it emits vastly more energy than the Sun.

11) Your friend asks what keeps the stars glowing, and you reply that they are releasing energy by

a) slowly contracting under their own gravity.
b) converting hydrogen to helium.
c) burning carbon like a log in a fireplace.
d) burning hydrogen to make water.
e) converting helium to carbon.

12) A planetary nebula, like the Ring Nebula shown in class, is

A. evidence that planets exist around other stars.
B. gas that is about to collapse and form planets.
C. gas ejected by a star which is becoming a white dwarf.
D. a very dense cloud with many organic molecules.
E. a giant molecular cloud that is about to form new stars.

13) Which of the following did Galileo NOT observe through his telescope?

A. sunspots
B. Titan's atmosphere
C. Venusian phases
D. Jovian satellites
E. lunar craters

14) The declination of a star is analogous to ( ) on Earth. (Fill in the parentheses).

A. latitude
B. longitude
C. the north pole
D. the south pole
E. the equator

15) During a phone conversation with my friend in London, England, he mentions that the full moon is beautiful tonight. It is 1 AM in London and 7 PM in College Park. It is clear so I look out my east window and see

A. the full moon.
B. a quarter moon.
C. a gibbous moon.
D. a crescent moon.
E. no moon.

16) A planet moves around the Sun in a circular orbit with a period of 27 years. How far is it from the Sun?

A. 27 AU.
B. 1/27 AU.
C. 5.25 AU.
D. 3 AU.
E. 9 AU.

17) The person who made accurate and continuous observations of the positions of stars and planets over a long period of time was

A. Nicolaus Copernicus.
B. Tycho Brahe.
C. Johannes Kepler.
D. Galileo Galilei.
E. Isaac Newton.

18) One of the most difficult problems for ancient astronomers to explain was the

A. cause of the seasons.
B. annual motion of the Sun on the ecliptic.
C. phases of the Moon.
D. eclipses of the Sun.
E. retrograde motions of the planets.

19) Newton's law of gravity is

A. F = GMm/r^2.
B. F = GMMr^2.
C. F = GMm/r.
D. F = GMr^2/m.
E. none of the above.

20) Suppose you are an astronaut taking a space walk to fix your spacecraft with a hammer. Your life-line breaks and the jets on your backpack are out of fuel. How would you return to your craft safely (without the help of someone else)?

A. Kick your feet in a cyclic pattern.

B. Fling your arms around in circles.

C. Throw the hammer in disgust at the spaceship.

D. Throw the hammer away from the spaceship.

E. Kiss your ship goodbye.

21) Pushing a shopping cart is much easier to do than pushing an automobile. The equation that expresses this fact is

A. P^2 = a^3.
B. F = ma.
C. F = GMm/r^2.
D. D = vt.
E. A = PI r^2.

22) The patterns or constellations of stars seen in each of our seasons are different. That fact demonstrates that

A. the Earth must rotate upon an axis.
B. the Earth must revolve on an orbit around the Sun.
C. the Earth must be a sphere.
D. the Sun must move relative to the stars.
E. there must be parallax angles for the stars.

23) The monthly cycle of phases of the Moon results primarily from

A. changes in the lunar orbital radius.

B. variations in the inclination of the lunar orbit.

C. changes in the lunar orbital velocity.

D. the changing angle of lunar illumination by the Sun.

E. the time the Moon is viewed.

24) Which has the highest energy?

A. red light
B. blue light
C. yellow light
D. green light
E. infrared light

25) Radio waves differ from visible light in that they

A. travel much faster through empty space.
B. travel much slower through empty space.
C. have a much longer wavelength.
D. have a much shorter wavelength.
E. are not electromagnetic waves like light is.

26) Which of the following correctly orders the radiation of the electromagnetic spectrum by decreasing wavelength (from longest wavelength to shortest)?

A. x-ray, radio, ultraviolet, visible, infrared, gamma ray.
B. infrared, x-ray, visible, radio, gamma ray, ultraviolet.
C. visible, infrared, gamma ray, ultraviolet, radio, x-ray.
D. radio, infrared, visible, ultraviolet, x-ray, gamma ray.
E. gamma ray, ultraviolet, x-ray, radio, visible, infrared.

27) A star radiates like a black-body at a temperature of about 6000 K. The brightest wavelength emitted by that star is about 500 nm. What would be the brightest wavelength emitted by another star whose temperature is 30,000 K?

A. 10 nm
B. 30 nm
C. 50 nm
D. 100 nm
E. 300 nm

30) In a few thousand years, the Earth's axis of rotation will not be pointing towards the star Polaris. This is because

A. the rotation of the Earth is slowing down.
B. the strength of the tides is increasing.
C. the Earth's axis is precessing.
D. the solar system will be on the other side of the Galaxy.
E. All of the above.

31) The picture below is of a telescope.

The lines with arrows identify the light path through the telescope. This is

A. a refractor.
B. an interferometer.
C. a reflector.
D. a diffractor.
E. a nanometer.

32) Excluding our Sun, the distances to the nearest stars are measured in

A. a few astronomical units.
B. hundreds of astronomical units.
C. a few light years.
D. hundreds of light years.
E. thousands of light years.

33) Planet A and B have the same mass. Planet B is twice the size of planet A. If you weigh 200 lbs on Planet A, how much would you weigh on Planet B?

A. 50 lbs.
B. 100 lbs.
C. 200 lbs.
D. 400 lbs.
E. 800 lbs.

If you have any questions regarding this page, send mail to: Scott Miller