Question

Name the device that is used to reverse the direction of current in the coil of a motor.

Answer 1

Hint: In order to solve this question we need to understand the definition of motor which states that motor is a device which converts electrical energy into mechanical energy with the help of magnetic field between coils. It runs on AC current and DC current both. It works on Faraday’s electromagnetic law which states that any change in flux through a loop or coil of a motor can induce current in coils and thereby produce torque in it so that mechanical energy could be produced.

Complete answer:
To understand which device reverse the current we need to know why there is a need to reverse direction in the motor. As stated motor works on principle of Faraday’s electromagnetic induction which states that flux change causes induction of current and producing torque.

Suppose one first changes flux and current induces in it but after some time there would be no flux change and hence current induced would vanish and motor stops spinning so if we reverse the direction of current suddenly after some time then there would be flux change continuously and hence motor keeps spinning on its axis. So the device that is used is known as Commutator or split ring. Commutator consists of two conductive arcs separated by an insulator.

Note:It should be remembered that current direction induced in loop according to Lenz’s law which states that current direction is such that it opposes the cause of its generation also the magnets here used to produce magnetic field is horse-shoe magnet so that flux change is continuous across motor.