PC 6 Problems

Mutual Inductance

Problem 1 A pair of adjacent coils has a mutual inductance of 1.5 H. If the current in one coil changes from 0 to 20 A in 0.5 s, what is the change of magnetic flux linked with the other coil?

Ans. 30 Wb

Problem 2 A long solenoid with 15 turns per cm has a small loop of area 2.0 cm^2 placed inside normal to the axis of the solenoid. The current carrying by the solenoid changes steadily from 2A to 4A in 0.1 s, What is the induced emf in loop while the current is changing?

Ans. 7.5 Micro Volt

Problem 3 Suppose a rectangular loop of sides 8 cm and 2 cm is stationary but the current feeding the electromagnet that produced the magnetic field is gradually reduced so that the field decreases from its initial value of 0.3 T at the rate of 0.02 T s^-1. If the cut is joined and the loop has a resistance of 1.6 ohm, how much power is dissipated by the loop as heat ? What is the source of this power ?

Ans. 6.4 * 10 ^-10 W