1. When a current of 2.5 A flows through a 0.5 H inductor, the flux produced is 80 Wb. Determine the number of turns.
2. A 1000 turn coil has a flux of 20 mWb linking it when carrying a current of 4 A. Calculate the coil inductance, and the emf induced when the current is reduced to zero in a time of 25 ms.