Exam Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) About how many stars are visible on a clear, dark night with the naked eye alone? 1) A) millions and millions B) a few thousand C) a few hundred D) tens of thousands E) a few dozen 2) If new Moon fell on March 2nd, what is the Moon's phase on March 14th? 2) A) waxing crescent B) waning crescent C) waxing gibbous D) first quarter E) full 3) When the sun rises it is located in the constellation Gemini. When the sun sets later that same day it will be 3) A) in the constellation Taurus. B) in the constellation Gemini. C) in the constellation Aries. D) in the constellation Leo. E) in the constellation Cancer. 4) Where would you be if the Sun sets for six continuous months, beginning on September 23rd? 4) A) Arctic Circle B) South Pole C) Equator D) North Pole E) Antarctic Circle 5) What conditions are necessary for an annular solar eclipse? 5) A) new moon on equator at apogee B) new moon on ecliptic at apogee C) new moon on equator at perigee D) full moon on ecliptic at perihelion E) new moon on ecliptic at perigee 6) Which statement about the length of a day is FALSE? 6) A) At the North Pole, the day lasts six months, then six months of night. B) At the equator, every day is twelve hours long, then twelve hours of night. C) The solar day is four minutes longer than the sidereal one. D) The sidereal day includes both the Earth's rotation and revolution around the Sun. E) For the United States, June 21st will be the longest day. 7) When the Moon is directly opposite the Sun in the sky, its phase is 7) A) first or third quarter. B) full. C) waxing or waning crescent - 1 -
D) waxing or waning gibbous. E) new. 8) Where on Earth can you observe all the stars in the sky over an entire year? 8) A) Equator B) Arctic Circle C) Tropic of Cancer D) North Pole E) Everyone on Earth can see the whole sky. 9) What conditions are necessary for a total solar eclipse? 9) A) new moon on ecliptic near aphelion B) new moon on equator at perigee C) new moon on ecliptic near perigee D) full moon on equator at perigee E) full moon on ecliptic near aphelion 10) A star with a large parallax 10) A) is not moving with respect to Earth. B) is at a short distance from Earth. C) is moving at a slow speed with respect to Earth. D) is at a great distance from Earth. E) is moving at a great speed with respect to Earth. 11) The most accurate Greek attempt to explain planetary motion was the model of: 11) A) Pythagoras. B) Aristotle. C) Erastothenes. D) Hipparchus. E) Ptolemy. 12) If the distance between two asteroids is doubled, the gravitational force they exert on each other will 12) A) be half as great. B) also be doubled. C) be one fourth as great. D) will be 1/16 as great. E) be four times greater. 13) What contribution to astronomy was made by Tycho Brahe? 13) A) The planets' orbits around the Sun are ellipses, not circles. B) His telescope revealed the moons of Jupiter before Galileo noted them. C) His observations of planetary motion with great accuracy proved circular orbits could not work. D) The Earth is not the center of the Universe. E) Retrograde motion must be explained by epicycles larger than those of Ptolemy. 14) What does Kepler's third law imply about planetary motion? 14) A) Planets further from the Sun orbit at a faster speed than planets closer to the Sun. B) Planets closer to the Sun orbit at a slower speed than planets further from the Sun. C) Planets further from the Sun orbit at a slower speed than planets closer to the Sun. D) All planets orbit the Sun at the same speed. - 2 -
E) This law implies nothing about a planet's motion. 15) On which of these assumptions do Ptolemy and Copernicus agree? 15) A) The Earth must be the center of all motion in the Cosmos. B) All orbits must be perfect circles. C) Venus must always stay between us and the Sun. D) The Sun was bigger than the Earth. E) The Sun must orbit us, but the planets do orbit the Sun. 16) The most famous prehistoric astronomical observatory is: 16) A) Stonehenge. B) Mount Rushmore. C) the Sphinx. D) Big Horn stone circle. E) Carcacol. 17) Geosynchronous satellites orbit at about four earth radii, where the earth's gravitational pull is: 17) A) 1/2 g. B) 1/16 g. C) 2 g. D) 1 g. E) 1/4 g. 18) The principal culture that transferred Greek astronomical knowledge to Renaissance Europe was: 18) A) Mayan. B) Byzantine. C) Islamic. D) Chinese. E) Mongol. 19) Which of these was a contribution of Newton to astronomy? 19) A) The Sun's gravity is greatest on a planet at perihelion, so the planet must speed up. B) His differential calculus lets us calculate planetary motions more accurately. C) The Moon pulls as strongly on us as we do on it. D) Artificial satellites could be put into orbit about the Earth. E) All of these were due to Newton's work. 20) The Ptolemaic model of the universe: 20) A) explained and predicted the motions of the planets with deferents and epicycles. B) describes the orbits of the planets as being ellipses, not circles. C) is the basis of our modern cosmology. D) always kept Mars and Mercury between the Earth and Sun. E) could not account for the stellar parallax observed by Hipparchus. 21) There are no x-ray telescopes on Earth because 21) A) we can't figure out how to direct an x-ray beam through space B) no one has yet invented an x-ray telescope that works C) x-rays don't penetrate Earth's atmosphere D) they are too expensive to build E) there are no astronomical objects that emit x-rays 22) The radiation our eyes are most sensitive to lies in the color 22) A) black at 227 nm. B) violet at 7,000 Angstroms. C) blue at 4,321 nanometers. D) red at 6563 Angstroms. E) yellow-green at about 550 nm. 23) The number of waves passing the observer per second is: 23) - 3 -
A) the wavelength in angstroms. B) the period in seconds. C) the energy in milliwatts. D) the amplitude in nm. E) the frequency in Hertz. 24) Increasing the temperature of a blackbody by a factor of 2 will increase its energy by a factor of 24) A) 8 B) 32 C) 4 D) E) 16 25) Very hot, young stars, like those in Messier 2 emit most of their light in which part of the electromagnetic spectrum? 25) A) the radio B) the x-ray C) the infrared D) the ultraviolet E) the visible 26) The total energy radiated by a blackbody depends on 26) A) the cube root of its temperature. B) the square root of its temperature. C) the fourth power of its temperature. D) the cube of its temperature. E) the square of its temperature. 27) Star A and star B have the same temperature, but star B is more luminous than star A. What can you infer about these two stars? 27) A) Star A must be redder. B) Star B must be bigger. C) Nothing can be inferred from the information given. D) Star A must be bigger. E) Star B must be redder. 28) If a wave's frequency doubles, its wavelength 28) A) is also doubled. B) is now 4 longer. C) becomes 16 longer. D) is halved. E) is unchanged, as c is constant. - 4 -
29) Star A has a temperature 1/2 that of star B, but star A is 3 times bigger than star B. Which statement below is correct? 29) A) Star A is redder and brighter than star B. B) Star A is redder and brighter than star B. C) Star A is bluer and dimmer than star B. D) Star A is redder and dimmer than star B. E) Star A and star B have the same color, but star A is brighter. 30) Of all the forms of electromagnetic radiation, the one with the lowest frequency is 30) A) radio waves. B) microwaves. C) visible light. D) gamma rays. E) ultraviolet rays. 31) Which of these is the classic continuous spectrum? 31) A) a fluorescent light B) a glowing nebula, such as M-42 C) sunlight D) a neon light E) a rainbow 32) Why are molecular lines more complex than elemental spectral lines? 32) A) Molecules can vibrate and rotate as well. B) Molecules have two or more atoms. C) Molecules are heavier than atoms. D) Molecules are the basis of life. E) Most of the universe is made of molecules, not individual atoms. 33) An emission spectrum can be used to identify a(n) 33) A) neutrino B) electron. C) proton D) neutron E) atom 34) The energy required to ionize a hydrogen atom whose electron is in the ground state (energy level 1) is 34) A) 12.1 ev B) 10.2 ev C) 13.6 ev D) 13.1 ev E) 12.75 ev 35) Which of the following type of electromagnetic radiation has the highest energy? 35) A) radio B) visible C) infrared D) ultraviolet E) x-ray 36) Spectral lines are often referred to as the stars' "fingerprints" because: 36) A) both are unique to their source. B) both can be easily categorized. C) fingerprints also consist of individual lines that make a pattern. D) both are characteristic of the individual that produced them. - 5 -
E) All of these are correct. 37) The particle which adds mass but no charge to the atomic nucleus is the: 37) A) proton. B) positron. C) neutron. D) alpha particle. E) neutrino. 38) What information about an astronomical object can be determined by observing its spectrum? 38) A) its radial motion B) its chemical composition C) its temperature D) whether it has a strong magnetic field E) all of the above 39) Emission lines of hydrogen that are found in the ultraviolet part of the electromagnetic spectrum are formed by electrons transitioning from 39) A) any level to level 1 B) any level to level 2 C) level 2 to any level D) any level to level 3 E) level 1 to any level 40) A hydrogen atom consists of an electron and a(n) 40) A) lepton. B) ion. C) proton. D) neutrino. E) neutron. - 6 -