Q1. What are sunspots and how are they related to the Sun's magnetic field? Is the magnetic field stronger weaker in sunspots? How does the temperature in a sunspot relate to the temperature in the rest of the photosphere? Explain the role of the Sun's differential rotation in formation of sunspots. Illustrate (briefly) the 22 year solar cycle, stating its essential features.

Q2. An aluminium can is filled to the brim with a liquid. The can and the liquid are heated so their temperatures change by the same amount. The can's initial volume at 5 °C is 3.5 × 10-4 m3. The coefficient of volume expansion for aluminium is 69 × 10-6 (C°)-1. While the can and liquid are heated to 78 °C, 9.5 × 10-6 m3 of liquid spills over. What is the coefficient of volume expansion of the liquid?