Question

explain the working of an electric motor.plzz help me.....it's urgent....

Answer 1

Here is the answer

The given attachment shows the construction of an electric motor.

$\bf{Structure :}$

Here,
A rectangular loop ABCD of copper wire with resistive coating is placed between the North Pole and South Pole of a strong magnet { Horseshoe magnet } such that the branches AB and CD are perpendicular to the direction of the magnetic field.

The ends of the loop are connected to the two halves , X and Y , of split rings - X and Y have resistive coating on their inner surfaces and are tightly fitted to the axle.
The outer conducting surfaces of X and Y are in contact with the two stationary brushes , E and F , respectively.

$\bf{Working :}$
When the circuit is completed with the plug key or switch the current flows in the direction
E ➡️A➡️B➡️C➡️D➡️ F.

As the magnetic field is directed from the north pole to the South Pole the force on AB is downward and that on CD is upward by the Fleming's Left Hand Rule. Hence , AB moves downward and CD upward.

These forces are equal in magnitude and opposite in direction, Therefore, As observed from the side AD , the loop ABCD and the axle start rotating in anticlockwise direction.

After half rotation, X and Y come in contact with brushes F and E respectively and the current flows in direction E-D-C-B-A-F.
Hence, the force on CD is downward and that on AB is upward.Therefore , the loop and the axle continue to rotate in the anticlockwise dierection.

After every half rotation, the current in the loop is reversed and the loop and the axle start rotating in the anticlockwise direction.

When the current is switched off, the loop stops rotating after some time.