a 4. A square loop of wire (side a) lies on a table, a distance s from a very long straight wire, which carries current I, as shown in the figure to the right. (a) Recalling that the magnetic ficld of an infinite wire is B = 4, find the flux of B through the loop. Hint: notice that B changes with distance from the wire! Also, take dA to be a strip of length a and height dr. (b) If someone now pulls the loop directly away from the wire, at speed v, what cmf, E, is generated? In what direction (clockwise or counterclockwise) docs the current flow? (Hint: note that v = (c) What if the loop is pulled to the right at speed v, instead of away?

a 4. A square loop of wire (side a) lies on a table, a distance s from a very long straight wire, which carries current I, as shown in the figure to the right. (a) Recalling that the magnetic ficld of an infinite wire is B = 4, find the flux of B through the loop. Hint: notice that B changes with distance from the wire! Also, take dA to be a strip of length a and height dr. (b) If someone now pulls the loop directly away from the wire, at speed v, what cmf, E, is generated? In what direction (clockwise or counterclockwise) docs the current flow? (Hint: note that v = (c) What if the loop is pulled to the right at speed v, instead of away?