Question

Explain the working of electric motor with a neat diagram.

Answer 1

Working of electric motor:

1) When electric is passed into the rectangular coil, magnetic field is produced around the coil.

2)The magnetic field of horse shoe type interacts with the magnetic field on the coil and causes the coil to rotate continuously.

3) If ABCD is in horizontal position, current from battery enters the coil through brush $B_1$ and commutator half ring C. Current flows in the direction ABCD and leaves via ring and brush $B_2$

4) The direction of current is from A to B, the current is from C to D. The force on side AB of the coil is in the downward direction.

Whereas the force on side CD of the coil is in the upward direction. ABCD rotate in anticlockwise direction.

5)While rotating when the coil reaches vertical positive then reaches vertical position then the brushes $B_1,B_2$ will touch the gap between the commutator rings and current to the coil is cut off. But the coil doesn't stop rotating because it has already gained momentum.

6) The coil CD comes on the left side and AB comes to the right side.

Again they come in contact with brush $B_1$ current direction is reversed.

7) The reversing of current in the coil is repeated after every half rotation, due to which the coil continue to rotate as long as current from the battery is passed through it.

The rotating shaft of electric motor can drive a large number of machine which are connected to it.