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1 | |
What causes the apparent twinkling of stars? |
| | A) | reflection of light |
| | B) | refraction of light |
| | C) | motion of stars |
| | D) | motion of earth |
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2 | |
Why don't the planets appear to twinkle? |
| | A) | Because a planet is not a source of light. |
| | B) | Because a planet appears as a point source of light. |
| | C) | Because the light reflected from a planet is able to refract. |
| | D) | Because a planet appears to be a larger source of light than a star. |
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3 | |
What does one light-year equal? The |
| | A) | time that light takes to reach the earth from the sun. |
| | B) | speed of light. |
| | C) | a ngle at which light falls. |
| | D) | distance that light travels in a year. |
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4 | |
What is the term for swirling clouds of hydrogen gas out of which stars are born? |
| | A) | protostar |
| | B) | constellation |
| | C) | comet |
| | D) | nebulae |
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5 | |
Select the correct statement about the interior of a star. |
| | A) | Moving outward from the center, the three regions of a star in the right order are core, convection zone, and, radiation zone. |
| | B) | The density of the radiation zone is about the same as that of water. |
| | C) | Convection zone is the densest of the three regions. |
| | D) | The core is the coldest of the three regions. |
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6 | |
Select the incorrect statement about brightness of stars. |
| | A) | A second-magnitude star appears to be brighter than a fifth-magnitude star. |
| | B) | The brightness of a star depends on the amount of energy it produces. |
| | C) | The absolute magnitude of a star depends on how far it is from the earth. |
| | D) | Relative to other stars the Sun has an average luminosity. |
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7 | |
Choose the correct statement about the color of a star. |
| | A) | Bluish stars are hotter than the reddish ones. |
| | B) | Color of a star tells us something about its distance from the earth. |
| | C) | The color of a star is independent of its chemical composition. |
| | D) | The yellow color of the sun indicates that it is one of the hottest stars. |
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8 | |
What is the likely future of the sun within the next 3 billion years? |
| | A) | stay the same |
| | B) | end up as a neutron star |
| | C) | end up as a black hole |
| | D) | end up as a white dwarf |
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9 | |
What is the source of energy in a star? |
| | A) | nuclear fission |
| | B) | nuclear fusion |
| | C) | combustion |
| | D) | oxidation |
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10 | |
What is the catastrophic explosion of a massive star called? |
| | A) | supernova |
| | B) | pulsar |
| | C) | black hole |
| | D) | planetary nebula |
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11 | |
A vast accumulation of hydrogen gas that is pulled together by gravity and will soon become a star is a |
| | A) | protostar |
| | B) | Cepheid variable |
| | C) | nova |
| | D) | planetary nebula |
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12 | |
A star begins a long, stable life when |
| | A) | it gets rid of it hydrogen. |
| | B) | its plasma cools, becoming neutral atoms. |
| | C) | expansion from energy released equals inward forces from gravity. |
| | D) | expansion from energy released exceeds inward forces from gravity. |
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13 | |
The sun is an ordinary, average star that is using its hydrogen fuel at a steady rate. As it ages, it will first evolve into a (an) |
| | A) | white dwarf. |
| | B) | red giant. |
| | C) | Cepheid variable. |
| | D) | nothing; it will always be as it is now. |
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14 | |
Main sequence stars that have a higher core temperature and use up their hydrogen more rapidly are |
| | A) | smaller, less massive stars. |
| | B) | larger, more massive stars. |
| | C) | typical, average mass stars. |
| | D) | There is no relationship between mass and higher temperatures. |
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15 | |
A red giant is an older star that has used up its supply of hydrogen in the core and now has a |
| | A) | carbon core. |
| | B) | iron core. |
| | C) | helium core. |
| | D) | core of solid, closely packed neutrons. |
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16 | |
An ordinary, average star such as the sun will eventually become a (an) |
| | A) | neutron star. |
| | B) | supernov |
| | C) | black hole. |
| | D) | cold lump of carbon. |
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17 | |
Today, the universe is understood to be |
| | A) | expanding at an increasing rate. |
| | B) | expanding at a decreasing rate. |
| | C) | steady, not expanding and not contracting. |
| | D) | contracting at a steady rate. |
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18 | |
The previously unknown force that is now understood to be expanding the universe is called |
| | A) | dark matter. |
| | B) | dark energy. |
| | C) | dark side of the force. |
| | D) | antimatter. |
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19 | |
Today, astronomers believe the universe is about how old? |
| | A) | 4.5 billion years. |
| | B) | 7 billion years. |
| | C) | 13 billion years. |
| | D) | 21 billion years. |
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20 | |
The different shapes of galaxies are today understood to be a result of |
| | A) | evolutionary stages that galaxies pass through as they age. |
| | B) | different conditions under which galaxies were formed. |
| | C) | gravitational interactions between passing galaxies. |
| | D) | the gravitational attraction of a black hole. |
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21 | |
Which of the following best describes the movement of galaxies since the Big Bang? |
| | A) | Galaxies are growing, which pushes them apart. |
| | B) | Space is constant and galaxies are moving away from each other. |
| | C) | Galaxies are moving away from the Milky Way through constant space. |
| | D) | Space is expanding and galaxies move with the expanding space. |
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22 | |
Why is the light year used as a referent unit of length in astronomy? |
| | A) | There are no referent points for using other units. |
| | B) | The distance that light travels in a year does not require a reference point. |
| | C) | The speed of light is constant in outer space. |
| | D) | All of the above. |
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23 | |
Choose the best description of a galaxy. |
| | A) | A group of several billion stars that form the basic unit of the universe. |
| | B) | The cluster of stars of which the sun is a part. |
| | C) | A symmetrical and tightly packed cluster of up to a million stars. |
| | D) | A group of up to a thousand stars that are gravitationally bound. |
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24 | |
Choose the correct statement about the big bang theory. |
| | A) | It occurred as a massive explosion at a point near the center of the universe. |
| | B) | Space did not exist before the big bang. |
| | C) | Space has always been three-dimensional. |
| | D) | Current data on the expansion of the universe contradicts the big bang theory. |
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25 | |
Choose the correct statement of the Hubble's law of expansion. |
| | A) | All parts of the universe expand at the same rate. |
| | B) | The outward motion of the galaxies closest to the center of the universe is the slowest. |
| | C) | The velocity with which a galaxy moves away from us is directly proportional to its distance from us. |
| | D) | The velocity with which a galaxy moves away from us is inversely proportional to its distance from us. |
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