ASTR 104 – January 2008 Wintersession – Test 1


Multiple-Choice Questions

(1) How wide are the largest mirrors currently in use for visible light telescopes?
a. 30 cm (12 in) across.
b. 2.5 m (100 in) across.
c. Over 10 m (30 ft) across.
d. About 300 m (1000 ft) across.

(2) In the course of one day, which objects rise in the East and set in the West?
a. Just the Sun.
b. The Sun and the Moon.
c. The Sun, the Moon, and the planets.
d. All celestial objects (except for circumpolar ones).

(3) Which astronomical objects move with respect to the celestial sphere?
a. Only the Sun and the Moon ever move.
c. The planets, the Sun, the Moon, and small objects like asteroids and comets; Stars practically don't move.
b. Nothing really moves on the celestial sphere, but all objects appear to move because of the Earth's rotation.
d. All objects do, but planets and stars move in different directions.

(4) What is a refracting telescope?
a. One that focuses incoming light with a primary lens rather than a mirror.
b. One that uses an extra lens to collect more light on the primary mirror.
c. One that produces blurred images because of the spreading of light.
d. One that produces negative images (dark stars on light backgrounds).

(5) Around what time did Copernicus and Tycho Brahe live?
a. The 1500's.
b. The 1800's.
c. The 5th century BC.
d. The 2nd century AD.

(6) What is the meridian?
a. The point directly overhead in the sky.
b. The line in the sky from North to South going through the Zenith.
c. The point on the celestial sphere where the Sun is on March 21st.
d. The line along which the Sun moves from sunrise to sunset.

(7) Which ancient people first emphasized the need for developing models to explain the way planets move?
a. The Mesopotamians.
b. The Greeks.
c. The Chinese.
d. The Egyptians.

(8) Which of the following were ancient astronomers looking for, but failed to see?
a. Sunspots on the Sun's surface.
b. Moons around Jupiter.
c. Parallax for stars.
d. Comets with tails.

(9) What is the main reason the Hubble Space Telescope gives great images?
a. It is outside the Earth's atmosphere.
b. It has the largest mirror ever built.
c. It is closer to the stars than Earth-bound telescopes.
d. It has the most sophisticated instruments currently in use.

(10) What is a plasma?
a. Matter which has been heated so much that most atoms are ionized.
b. A solid which is so cold that all atoms are stuck together.
c. A liquid which is so sticky that it is almost a solid.
d. A gas which is about to condensate into a liquid.

(11) If you looked at the sky from the Space Station outside the Earth's atmosphere, which objects would twinkle?
a. Stars would twinkle, but not planets.
b. Planets would twinkle, but not stars.
c. Neither stars nor planets.
d. Both stars and planets.

(12) The main reason for building telescopes with very wide primary mirrors is that
a. We get a larger magnification of the images.
b. We can see a larger portion of the sky at the same time.
c. We get brighter, sharper images of astronomical objects.
d. They are not affected by atmospheric turbulence.

(13) Do we consider Kepler's laws for the solar system to be correct?
a. Basically yes, because except for small corrections they have passed all tests.
b. No, because those laws do not follow the teaching of Aristotle.
c. No, because Kepler in part used guesswork to arrive at those laws.
d. No, because the model he proposed is heliocentric.

(14) If you watched the sky for several hours one night, which of these stars would not change position?
a. Sirius.
b. Polaris.
c. Alpha Centauri.
d. None, they would all change position over time.

(15) Which of the following produce an emission line spectrum?
a. Hot spectroscopes.
b. Hot solids, liquids, and very dense gases.
c. Hot thin gases.
d. Cool gases and liquids.

(16) Can amateur astronomers make new astronomical discoveries today?
a. Yes, but they have to connect their small telescopes into large networks.
b. Yes, for example by spotting unexpected objects like novas or asteroids.
c. No, because their telescopes are too small compared with professional ones.
d. No, because amateurs do not have access to good observation sites.

(17) Does the speed of a planet along its orbit vary?
a. No, each planet always moves at the same speed.
b. Yes, it moves faster when it is closer to the Sun.
c. Yes, it moves faster when it is farther from the Sun.
d. Yes, it moves faster when it is moving toward the Sun.

(18) Which planets were already known before the telescope was invented?
a. Venus, Mars, Jupiter and Saturn.
b. Mercury, Venus, Mars, Jupiter and Saturn.
c. Venus, Mars, Jupiter, Saturn, Uranus and Neptune.
d. Mercury, Venus, Mars, Jupiter, Saturn, Uranus and Neptune.

(19) A red apple has that color because red light is
a. Emitted by the apple.
b. Transmitted by the apple.
c. Reflected by the apple.
d. Absorbed by the apple.

(20) A piece of red glass has that color when you look through it because red light is
a. Emitted by the glass.
b. Transmitted by the glass.
c. Reflected by the glass.
d. Absorbed by the glass.

(21) Which of the following can you do to improve the angular resolution of a telescope?
a. Use a reflecting telescope rather than a refracting one.
b. Increase the diameter of the telescope's primary mirror.
c. Change the eyepiece to get a larger magnification.
d. Increase the focal length of the primary mirror.

(22) What is declination?
a. The downward motion of a star as it sets below the horizon.
b. The Latin name for a star, based on the constellation it is located in.
c. The latitude of the point on the Earth where a telescope is located.
d. The angle at which an object is located above or below the Celestial Equator.

(23) What kinds of objects can experience a force of gravity?
a. Every object exerts a force of gravity on every other one.
b. Only objects that are on or near the surface of a planet.
c. Only planets moving around a star, or moons around a planet.
d. Objects in either one of the two situations in (b) or (c).

(24) Can you apply Kepler's laws to the orbits of moons around a planet?
a. Yes, but only if the planet is orbiting the Sun at the same time.
b. Yes, because the force involved is still the force of gravity.
c. No, because Kepler wrote down his laws only for planets.
d. No, because moons are too small.

(25) What is Stonehenge?
a. A cave where paleolitic paintings including stars were found.
b. A place in Wyoming where the Indians built a Medicine Wheel.
c. A circular structure of tall stones in Southern England.
d. A prehistoric era, during which the oldest sites were built.

(26) Approximately how many stars can we see with the naked eye, in very good viewing conditions?
a. A few hundred.
b. A few thousands.
c. About 1 million.
d. About 100 billion.

(27) What happens to the radiation emitted by a dense object if its temperature rises?
a. The total amount stays constant, but its peak frequency increases.
b. Its peak frequency stays constant, but the total amount increases.
c. Both its peak frequency and the total amount of radiation increase.
d. It does not change, but it stops when the object melts and falls apart.

(28) What did Galileo discover about the Moon?
a. That it revolves around the Earth, not the Sun.
b. That there are features such as craters on its surface.
c. That there are meteors orbiting around it.
d. That it goes through different phases every month.

(29) As a planet revolves around the Sun, does the Sun also move?
a. No, because in this case the Sun is the center of attraction.
b. Yes, the Sun feels the same pull but it is so massive that it moves much less.
c. Yes, the Sun feels the same pull and moves as much as the planet does.
d. Maybe, but there is no way for us to find out because the Earth itself is moving.

(30) Why is Aristarchus remembered in the history of Astronomy?
a. He believed in a heliocentric model already in the 3rd century BC.
b. He made careful observations of the planets and discovered epicycles.
c. He proved that the geocentric model of the solar system was correct.
d. He was the first person who used a telescope in astronomy.

Short-Answer Questions

(31) What is the ecliptic?


(32) In what ways was Copernicus' model of the Solar System similar or different from our current one?


(33) What is the difference between a hydrogen atom and a helium atom?


(34) What is the difference between radio waves and visible light waves?


(35) What is a photon?