a. The galvanometer momentarily deflects, then returns to zero. b. There is no response. c. The galvanometer momentarily deflects in the opposite direction as it did when the switch was closed.
Work Step by Step
Current is induced only when there is a change in the magnetic field within the secondary coils. a. When the switch in the first circuit is closed, the magnetic field increases. The galvanometer needle flicks in one direction while the field is changing. b. When the current in the primary coil is steady, the magnetic field is steady, and no current is induced. c. When the switch is opened, the magnetic field falls to zero. The galvanometer needle swings in the opposite direction.