The core of the Sun is1) at the same temperature and density as the

surface.2) at the same temperature but denser than the

surface.3) hotter and denser than the surface.4) constantly rising to the surface through

convection.5) composed of iron.

Sunspots are cooler than thesurrounding solar surface

because1. they are regions where convection

carries cooler material downward.2. strong magnetic fields slow convection

and prevent hot plasma from enteringthe region.

3. magnetic fields trap ionized gases thatabsorb light.

4. there is less fusion occurring there.5. mag

How does the Sun generateenergy today?

1. nuclear fission2. nuclear fusion3. chemical reactions4. gravitational contraction5. gradually expanding in size

How do human-built nuclearpower plants on Earth generate

energy?1. chemical reactions2. nuclear fusion3. nuclear fission4. converting kinetic energy into

electricity5. converting gravitational potential

energy into electricity

At the center of the Sun, fusionconverts hydrogen into

1. hydrogen compounds.2. plasma.3. radiation and elements like carbon

and nitrogen.4. radioactive elements like uranium and

plutonium.5. helium, energy, and neutrinos.

Suppose you put two protons near eachother. Because of the electromagnetic

force, the two protons will1. collide.2. remain stationary.3. attract each other.4. repel each other.5. join together to form a nucleus.

Since all stars begin their lives with the samebasic composition, what characteristic most

determines how they will differ?

1. location where they are formed2. time they are formed3. luminosity they are formed with4. mass they are formed with5. color they are formed with

A star's luminosity is the

1. apparent brightness of the star in oursky.

2. surface temperature of the star.3. lifetime of the star.4. total amount of light that the star will

radiate over its entire lifetime.5. total amount of light that the star

radiates each second.

The spectral sequence sortsstars according to

1. mass.2. surface temperature.3. luminosity.4. core temperature.5. radius.

Which of the following terms is given to a pair ofstars that appear to change positions in the sky,indicating that they are orbiting one another?

1. visual binary2. eclipsing binary3. spectroscopic binary4. double star5. none of the above

Which of the following best describes theaxes of a Hertzsprung-Russell (H-R)

diagram?1. surface temperature on the horizontal

axis and luminosity on the vertical axis2. mass on the horizontal axis and

luminosity on the vertical axis3. surface temperature on the horizontal

axis and radius on the vertical axis4. mass on the horizontal axis and ste

On a Hertzsprung-Russell diagram, wherewould we find stars that are cool and dim?

1. upper right2. lower right3. upper left4. lower left

On a Hertzsprung-Russell diagram, wherewould we find red giant stars?

1. upper right2. lower right3. upper left4. lower left

Which of the following statements aboutcomets and asteroids is true?

1. Only asteroids collide with Earth.2. Comets are balls of ice and dust.3. Most of the trillions of comets in our

solar system have tails.4. All asteroids lie in the asteroid belt

between Mars and Jupiter.5. There are about 1 million known

asteroids in the solar system

Why do asteroids and comets differ incomposition?

1. Asteroids formed inside the frost line,while comets formed outside.

2. Asteroids and comets formed atdifferent times.

3. Comets formed from the joviannebula, while asteroids did not.

4. Comets are much larger thanasteroids.

5. Asteroids are much larger than c

If an object's velocity isdoubled, its momentum is1. halved.2. unchanged.3. doubled.4. quadrupled.5. dependent on its acceleration.

You are standing on a scale in anelevator. Suddenly you notice your

weight decreases. What do you conclude?1. The elevator is accelerating upwards.2. The elevator is moving at a constant

velocity upwards.3. The elevator is accelerating

downwards.4. The elevator is moving at a constant

velocity downwards.5. Your diet is working.

What quantities does angularmomentum depend upon?1. mass and velocity2. mass, velocity, and radius3. force and radius4. force, velocity, and radius5. momentum and angular velocity

The amount of gravitational potentialenergy released as an object falls

depends on1. the distance it falls.2. its speed at the time it begins falling.3. the distance it falls and its speed at the

time it begins falling.4. neither the distance it falls nor its

speed at the time it begins falling.

Which of the following statementscorrectly describes the law of conservation

of energy?1. An object always has the same amount of

energy.2. Energy can change between many different

forms, such as potential, kinetic, andthermal, but it is ultimately destroyed.

3. The total quantity of energy in the universenever changes.

4. The fact that you can fuse hydrogen intohelium to produce energy means that helium canbe turned into hydrogen to produce energy.

According to what we now know fromNewton's laws, which of the following bestexplains why Kepler's second law is true?

1. A planet's total orbital energy must beconserved as it moves around its orbit.

2. Orbits must be elliptical in shape.3. Gravity is an inverse cube law.4. This effect happens because of the

influence of other planets on aparticular planet's orbit.

The mass of Jupiter can becalculated by

1. measuring the orbital period and distance ofJupiter's orbit around the Sun.

2. measuring the orbital period and distance ofone of Jupiter's moons.

3. measuring the orbital speed of one ofJupiter's moons.

4. knowing the Sun's mass and measuringhow Jupiter's speed changes during its ellipticalorbit around the Sun.

The frequency of a wave is

1. the number of peaks passing by anypoint each second.

2. measured in cycles per second.3. measured in hertz (Hz).4. equal to the speed of the wave

divided by the wavelength of thewave.

5. all of the above

The wavelength of a wave is

1. how strong the wave is.2. the distance between a peak of the

wave and the next trough.3. the distance between two adjacent

peaks of the wave.4. the distance between where the wave

is emitted and where it is absorbed.5. equal to the speed of the wave times

the

When an atom loses anelectron, it becomes

1. sublimated.2. dissociated.3. ionized.4. an isotope.5. a plasma.

How can an electron in an atom loseenergy to go from a higher energy level

to a lower energy level?1. It loses kinetic energy.2. It releases a light equal in energy to its

own energy drop.3. It absorbs a light equal in energy to its

own energy drop.4. It loses gravitational potential energy.5. It exchanges gravitational potential

energy for kinetic energy.

Everything looks red througha red filter because

1. the filter emits red light and absorbsother colors.

2. the filter absorbs red light and emitsother colors.

3. the filter transmits red light andabsorbs other colors.

4. the filter reflects red light andtransmits other colors.

Which of the following statements aboutX rays and radio waves is not true?

1. Neither X rays nor radio waves canpenetrate Earth's atmosphere.

2. X rays have shorter wavelengths than radiowaves.

3. X rays and radio waves are both forms oflight, or electromagnetic radiation.

4. X rays have higher frequency than radiowaves.

5. X rays have higher energy than radio waves.

We can see each other in the classroomright now because we

1. emit thermal radiation.2. emit visible light.3. emit infrared light.4. reflect visible light.5. reflect infrared light.

If you heat a gas so that collisions are continuallybumping electrons to higher energy levels, whenthe electrons fall back to lower energy levels the

gas produces1. thermal radiation.2. an absorption line spectrum.3. an emission line spectrum.4. X rays.5. radio waves.

Where does nuclear fusionoccur in the Sun?

1. on the surface2. anywhere below the surface3. in its core4. just above the visible surface5. all of the above

Which planet has the highest averagesurface temperature, and why?

1. Mercury, because it is closest to theSun

2. Mercury, because of its dense carbondioxide atmosphere

3. Venus, because of its dense carbondioxide atmosphere

4. Mars, because of its red color5. Jupiter, because it is so big

Which planet has a ringsystem?

1. Jupiter2. Saturn3. Uranus4. Neptune5. All of the above

Which of the following is not acharacteristic of the inner planets?

1. They are relatively smaller than theouter planets.

2. They all have solid, rocky surfaces.3. Their orbits are relatively closely

spaced.4. They all have substantial

atmospheres.5. They have very few, if any, satellites.

The farthest bright galaxies that moderntelescopes are capable of seeing are up to

1. 1 million light yearsaway

2. 10 million light yearsaway

3. 1 billion light yearsaway

4. 10 billion light yearsaway

5. 1 trillion light yearsaway

Earth is made mostly of metals and rocks.Where did this material come from?

1. It was produced in theBig Bang.

2. It was created bychemical reactions ininterstellar space.

3. It was produced bynuclear fusion in stars.

4. It was made by our Sun.5. It was made by nuclear

fission of uranium andother radioactivematerials

Suppose we look at a photograph of many galaxies.Assuming that all galaxies formed at about the same

time, which galaxy in the picture is the youngest?

1. the one that isfarthest away

2. the one that isreddest in color

3. the one that isbluest in color

4. the one that isclosest to us

5. the one thatappears smallest insize

Our solar system is located inthe center of the Milky Way

Galaxy.1. True2. False

Which of the following statements about thecelestial equator is true at all latitudes?

1. It lies along the band of lightwe call the Milky Way.

2. It represents an extension ofEarth's equator onto thecelestial sphere.

3. It cuts the dome of your localsky exactly in half.

4. It extends from your horizondue east, through your zenith,to your horizon due west.

5. It extends from your horizondue north, through yourzenith, to your horizon duesouth.

If it is midnight in New York,it is

1. daytime in Sydney,Australia.

2. midnight in Sydney,Australia.

3. midnight in LosAngeles.

4. midday in Rio deJaneiro, Brazil.

5. midnight everywhere.

Orion is visible on winter eveningsbut not summer evenings because of

1. interference from the fullmoon.

2. the tilt of Earth's axis.3. the location of Earth in its

orbit.4. the precession of Earth's

axis.5. baseball on television.

If the Moon is setting at 6 A.M., thephase of the Moon must be

1. first quarter.2. third quarter.3. full.4. new.5. waning crescent.

At approximately what time would afull moon be on your meridian?

1. 6 A.M.2. 9 A.M.3. noon4. 6 P.M.5. midnight

Which of the following statements aboutthe Moon is true?

1. The Moon goes through acycle of phases because italways has the same sidefacing Earth.

2. If you see a full Moon fromNorth America, someonein South America wouldsee a new moon.

3. The Moon's distance fromEarth varies during itsorbit.

4. The Moon is visible only atnight.

5. The side of the Moonfacing away from Earth isin perpetual darkness.

What effect or effects would be mostsignificant if the Moon's orbital plane were

exactly the same as the ecliptic plane?

1. Solar eclipses wouldbe much rarer.

2. Solar eclipses wouldbe much morefrequent.

3. Total solar eclipseswould last muchlonger.

4. both 1 and 35. both 2 and 3

What happens during the apparentretrograde motion of a planet?

1. The planet rises in the westand sets in the east.

2. The planet appears to moveeastward with respect to thestars over a period of manynights.

3. The planet moves backwardthrough the sky.

4. The planet moves backwardin its orbit around the Sun.

5. The planet moves throughconstellations that are not partof the zodiac.

We can't detect stellar parallax with naked-eyeobservations. Which of the following would

make parallax easier to observe?1. increasing the size of Earth's

orbit2. speeding up Earth's orbital

motion3. slowing down Earth's orbital

motion4. Speeding up the precession

of Earth's axis5. getting away from

streetlights

Why did Ptolemy have the planets orbitingEarth on "circles upon circles" in his model of

the universe?1. to explain why more distant

planets take longer to make acircuit through the constellationsof the zodiac

2. to explain the fact that planetssometimes appear to movewestward, rather than eastward,relative to the stars in our sky

3. to explain why the Greeks wereunable to detect stellar parallax

4. To properly account for thevarying distances of the planetsfrom Earth

5. To explain why Venus goesthrough phases as seen fromEarth

He developed a system for predictingplanetary positions that remained in use for

some 1,500 years.1. Tycho Brahe2. Copernicus3. Kepler4. Galileo5. Ptolemy

He discovered that the orbitsof planets are ellipses.

1. Tycho Brahe2. Copernicus3. Kepler4. Galileo5. Ptolemy

One of the "nails in the coffin" for theEarth-centered universe was

1. the retrograde motion ofthe planets.

2. the phases of the Moon.3. eclipses of the Sun.4. Galileo's observation of

stars in the Milky Way.5. Galileo's observations of

the moons of Jupiter.