1 A) A = 2Br B) A = Br2 C) A = 4Br2 D) A = 4/3 Br3 2 A) A gathers 1/2 the light that B does. B) A gathers twice the light that B does. C) A gathers 4 times the light that B does. D) A gathers 1/4th as much light as B does. 3 A) fainter sources. B) more distant sources. C) finer details in sources. D) larger sources. 4 A) make its mirror bigger. B) make its mirror smaller. C) replace its mirror with a lens of the same diameter. D) observe objects using longer wavelengths. 5 A) irregularities in the density of layers of Earth's atmosphere, rapidly refracting the light. B) the flickering fusion process in the stars. C) a purely physiological reaction in the eye. D) none of these answers are correct. 6 A) Reflection B) Refraction C) Diffraction D) Distraction 7 A) A reflecting telescope uses a lens to focus light; a refracting telescope uses a mirror. B) A reflecting telescope uses a mirror to focus light; a refracting telescope uses a lens. C) Both use a mirror to focus light, but a reflecting telescope uses mirrors elsewhere to bend light. D) There is no difference. "Refracting" is an outmoded way of saying "reflecting." 8 A) faster B) slower C) at the same speed D) perpendicular to 9 A) Lenses are more expensive to make than mirrors. B) Most transparent materials focus light of different colors to different spots. C) Lenses can only be supported by their edges, making them sag in the middle (mirrors can be supported from behind). D) All of the above. 10 A) Its two widely-spaced mirrors act like one giant telescope with increased collecting area. B) Its two widely-spaced mirrors act like one giant telescope with increased resolving power. C) By putting one mirror above the other you can make the instrument much smaller. D) It can detect light at wavelengths not available to single telescopes. 11 A) dust clouds in space B) hot gas surrounding black holes C) cold interstellar gas clouds D) all of the above 12 A) Yes, because they can penetrate gas clouds. B) No, because no astronomical objects emit x-rays. C) No, because x-rays cannot get through the Earth's atmosphere. D) No, because astronomers have not yet devised detectors for x-rays. 13 A) Mirrors can't be built accurately enough. B) The atmosphere blurs the image, decreasing the resolving power. C) Mirrors cannot collect enough light to reach their theoretical expectations. D) The theoretical value can only be reached when there is a Full Moon. 14 A) Actuary observing B) Interferometry. C) Refraction D) Adaptive Optics 15 A) They are much less expensive than ground-based observatories. B) They can last forever. C) To avoid atmospheric blurring. D) There is no good reason to build a space-based observatory.
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