Question

principle and working of electric motor

Answer 1

Principal: when A coil carring current is placed in a magnetic field ,it experiences a torque (force) as a result the begins to rotate ..

Answer 2

${\huge{\mathsf{\blue{WORKING\::-}}}}$

Current in the coil ABCD enters from the source battery through brush 'X' and return back through brush 'Y'.

As a result the direction of the current in arm AB of the coil and CD of the coil is opposite.

Now according to Fleming's left hand rule ,we can find out the force experienced by the coil.The force acting on arm AB pushes it downwards while the force acting on arm CD pushes it upwards. As a result ,the coil and the axle,rotate in anti- clockwise direction. So,when half the rotation is completed, Q makes content with brush X and P with brush Y. As a result ,the rings acts as a commutator , which reversed the direction of of the current.

The reversal of current also reverses the direction of force acting on the two arms AB and CD.

So,the arm AB of the quarrel that was earlier pushed down is now pushed up and the arm CD previously pushed up is now pushed down.

As a result of this, the coil and the axle rotate half a turn more in the same direction.The reversing of the current is repeated at each half rotation, so,the quail along with axle continue to move in same direction.

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