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