Only 2 problems
1. Suppose a tightly wound rectangular coil of 80 turns has dimensions 10 cm by 35 cm. In time t = 0.08 seconds the plane of the coil is rotated from a position where it makes a 30◦ angle with a magnetic field of 0.775 T to a position perpendicular to the field. What is the average emf induced in the coil?
2. Inthefigureaboveemf=80V,R=200Ω,andL=0.44H.WithswitchS2 open,switchS1 isleft closed until a constant current is established. Then switch S2 is closed and S1 is opened, taking the battery out of the circuit.
a) Find the initial current in the resistor, just after S2 is closed and S1 is opened.
b) Find the current in the resistor at time t = 1.2 × 10−4 seconds.
c) What is the potential difference between points b and c at time t = 1.20 × 10−4 seconds.