Q1. What are sunspots and how are they related to Sun's magnetic field? Is a magnetic field stronger weaker in sunspots? How does the temperature in a sunspot relate to the temperature in the rest of the photosphere? Illustrate the role of the Sun's differential rotation in the formation of sunspots. Explain (briefly) the 22 year solar cycle, stating its essential features.
Q2. A long wire lying along the x-axis carries a current of 1.60 A in the +x direction. There is a uniform magnetic field present, given by B=0.003i + 0.004j + 0.002k, where i, j, k are the unit vectors along the Cartesian coordinate axes') in units of Tesla. Estimate the y-component of magnetic force acting on a segment of wire of length L = 18.0 cm.