Question

In fig. P and S are two coils. What shall be the direction of induced momentary current in S immediately after the switch is closed, (ii) if the switch is opened, after it the been closed for some time,

Answer 1

When switch is closed, current in P grows. Induced current is S will oppos the growth. Hence the current in S must be anticlockwise. When switch is opened, current in P dacays from maximum to zero. Induced current in S will oppose the decay. Hence current in S must be clockwise.