LENZ’S LAW INDUCED CURRENT IS ALWAYS FLOWS IN SUCH A DIRECTION SO AS TO OPPOSE THE CHANGE (MOTION) PRODUCING IT
DIRECTION OF INDUCED CURRENT When the North pole of a magnet moved into a solenoid, the end P becomes a North pole to produce a force of repulsion to oppose the change of magnet motion. Galvanometer is deflected to ………
DYNAMO APPLICATION OF ELECTROMAGNETIC INDUCTION Dc generator
The coil is rotated by external force and cuts the magnetic force. An alternate e.m.f is induced in the coil, but a dc output is obtained by using split ring commutator. The two halves of the split ring commutator exchange contact with the carbon brushes every half rotation The cutting of magnetic flux is maximum when the coil is at horizontal position. It decreases when as the coil rotates from horizontal to vertical position. Magnitude of induced flux changes whenever the position of coil changes.
If the split ring commutator is replaced with two slip rings, the output is ac. The slip rings are always in contact with the same carbon brush. The output current changes direction every half turn.