1. Question 1: Why is it so important that the temperature in the center of the sun is more than 10 million K? Review Quiz No. 12 :60 1.Because otherwise it would not radiate optical, but only infrared light. 2.Because otherwise it would radiate mostly ultraviolet light. 3.Because otherwise it would not be hot enough to bring the surface to a boil (as seen in the granulation). 4.Because this temperature is needed to smash nuclei into each other to keep fission reactions going. 5.Because this temperature is needed to smash protons into each other to keep fusion reactions going.

2. Question 2: Sun spots appear dark because the gas in those regions … than on average in the photosphere. :45 1.is denser 2.is less dense 3.is hotter 4.is colder 5.contains more helium

3. Question 3: Sun spot activity is related to … :45 1.extraordinarily strong electric fields. 2.extraordinarily strong magnetic fields. 3.extraordinarily weak electric fields. 4.extraordinarily weak magnetic fields. 5.opaque gas blobs hiding part of the photosphere from our direct view.

4. Question 4: The Maunder Butterfly Diagram illustrates … :45 1.the annual migration patterns of butterflies in North America. 2.the direction of magnetic fields on the sun. 3.the direction of electric fields on the sun. 4.the changing number and preferred latitude of sun spots throughout the solar cycle. 5.deviations of the duration of solar cycles from the average value.