Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 1 Announcements: Exam #2: Thursday, April 5 th ! Chp. 3, 11 Take the practice quizzes online at: Select a chapter (3 and 11) and follow links to online quizzes. Pick up HW solutions and study guide.

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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 3 1. Which photon has the highest energy? a. ultraviolet b. visible c. x-ray d. infrared e. radio 2. Which photon has the longest wavelength? a. ultraviolet b. visible c. x-ray d. infrared e. radio

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 4 3. Rank the following types of radiation is order of increasing 1) wavelength, 2) frequency, and 3) energy: microwave, visible, x-ray, radio, gamma ray, infrared A)gamma ray, x-ray, visible, infrared, microwave microwave, infrared, visible, x-ray, gamma ray B) microwave, infrared, visible, x-ray, gamma ray gamma ray, x-ray, visible, infrared, microwave C) gamma ray, x-ray, visible, infrared, microwave microwave, infrared, visible, x-ray, gamma ray gamma ray, x-ray, visible, infrared, microwave

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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 6 4. Stars emit radiation very much like a perfect blackbody. Our Sun has a surface temperature of approximately 6000 degrees Kelvin. At what wavelength does the Sun emit most of its radiation? a) 6000 nm b) 1.8 ×10 10 nm c) 1.5×10 9 nm d) nm e) 500 nm

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 7 5. When something is what we usually call “red hot”, it is hotter than something that is a) “blue” hot b) “white” hot c) neither of these d) both of these

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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 9 6. The Earth’s atmosphere is opaque to the ________ part of the electromagnetic spectrum: a)Visible b)X-Ray c)All of the above d)None of the above

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Which of the following statements is true with regards to Blackbody radiation? a)A blackbody emits relatively more energy at longer wavelengths as it heats up. b)A blackbody emits energy at all wavelengths c)The shape of the blackbody spectrum depends on what the source is made of. d)All of the above e)None of the above

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Which transitions were responsible for each of these absorption lines? a) A: 1-2 B: 2-4 C: 1-4 b) A: 1-4 B: 2-4 C: 1-2 c) A: 4-1 B: 4-2 C: 2-1

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Two stars orbiting one another. The diagram shows the orbital motion of one of the stars, and four different positions are marked (A, B, C, D). At which position is the light from the star redshifted? blueshifted? not shifted at all? a) A, C, B/D b) C, A, B/D c) B, D, A/C d) D, B, A/C B D CA

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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Emission and Absorption lines are produced when _____ interact with _____. a) protons, electrons b) neutrons, protons c) neutrons, photons d) electrons, photons

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display An incandescent bulb, fluorescent light, and the Sun emit ________, ________, and _________ spectra, respectively. a)Continuous, emission, absorption b)Continuous, absorption, emission c)Continuous, continuous, continuous d)Absorption, emission, continuous e)Absorption, emission, absoprtion

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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Two stars orbiting one another. The diagram shows the orbital motion of one of the stars, and four different positions are marked (A, B, C, D). At which position is the light from the star redshifted? blueshifted? not shifted at all? a) A, C, B/D b) C, A, B/D c) B, D, A/C d) D, B, A/C B D C A

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Which of the following statements about the Sun’s atmosphere is false? a) The chromosphere is the region in which the colors producing white light are generated. b) The photosphere is where most of the photons escape into space c) The corona consists of very low density gas d) The temperature of the corona is higher than the temperature of the Sun’s “surface”.

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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display The Sun produces its energy from a)Electric currents generated in its core b)Chemical reactions (oxidation reactions) producing flames c)Fusion of hydrogen into helium d)Disintegration of helium into hydrogen

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display About how many years elapse between times of maximum solar activity? a)30 b)11 c)22 d)1 e)None of the above.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display The Butterfly Diagram plots a) Number of sunspots as a function of time b) Number of sunspots as a function of magnetic field strength c) Rotation rate as a function of latitude d) Sunspot latitude as a function of time.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Which of the following about the sunspot cycle is not true? a) The number of spots rises and falls every 11 years. b) The pattern of the magnetic polarity of the spots repeats every 22 years. c) spots are located in regions of high magnetic activity d) spots are more readily seen near the rotational poles of the Sun where magnetic field lines are concentrated

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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display The Maunder Minimum refers to a) Times of low solar activity that occur every 11 years. b)Times of low solar activity that occur every 22 years c)The region in the solar atmosphere where the temperature is lowest. d)An extended period of time in the 1600’s during which the Sun had anomalously low activity levels.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display The Sun’s activity cycle is a result of: a) Magnetism and Differential Rotation b) Gas Pressure and Differential Rotation c) Coupling of the magnetic field of the Earth and Sun. d) Global Warming

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 27 1 H+ 1 H  2 H+e + + e 2 H+ 1 H  3 He+  3 He+ 3 He  4 He+2 1 H 20. What’s missing? a) 1 H b) 2 H c) 3 He d) 4 He ?

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 28 Miscellaneous

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Sunspots are A. regions where the gas is considerably cooler (by as much as 1500 K) than the surroundings. B. regions where the gas is considerably hotter than the surroundings. C. regions where the magnetic field is stronger. D. both a and c. E. both b and c.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display The four hydrogen nuclei which are fused together are more massive than the helium nucleus which they make. What happens to the missing mass? A. It is converted to energy. B. It is ejected from the star in flare activity. C. It reappears later as neutrinos. D. It is re-supplied to the Sun by meteoroid impacts.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display In the proton-proton chain, how many protons are required to make a helium nucleus? A. 4. B. 2. C. 3. D. 5.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Which of the following statements about solar neutrinos is not true? A)They are produced by the proton-proton chain B)Their interaction with matter is extremely weak C)They carry electric charge D)They provide information about the solar interior E)They carry energy.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display The energy emitted by thermonuclear processes in the core of the Sun takes thousands or even millions of years to emerge from the surface because a) it is circling in the gravitational field of the Sun b) it loses energy due to convection, conduction, and radiation c) of the Sun’s enormous radiation d) it is absorbed and re-emitted countless times along the way.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display The temperature in and around the Sun a) drops continuously as you move outward b) rises continuously as you move outward c) drops as you move from the center to the photosphere, then rises above the photosphere. d) increases as you move from the center to the photosphere, then drops above the photosphere.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 35 B. Unfiltered light; optical; sunspots; photosphere A. Filtered optical (H emission); plages; chromosphere C. UV emission; coronal holes, prominences; corona D. X-Ray emission; coronal holes, prominences; corona B 2. A 3. D 4. C

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display C 2. E 3. A 4. E 5. C 6. B 7. B 8. B 9. C 10. D 11. A 12. A 13. A 14. C 15. B 16. D 17. D 18. D 19. A 20. C 21. D 22. A 23. A 24. C 25. D 26. C Answer Key