Name: Revisiting Ohm's Law & Resistivity
Uploaded: 2019-07-19
Duration: 4 min 5 s
Description: The entire domain of the science of electric current can be explained using Ohm’s law, that’s how powerful this discovery was. We will revise this once again.

Question

Explain the principle and working of electric motor, by drawing its labelled diagram.

Accepted Answer

Principle Of Electric Motor: Electric motor works on the principle that when a rectangular coil is placed in a magnetic field and current is passed through it. A force acts on the coil which rotates it continuously.
The electric motor is a device that converts electrical energy to mechanical energy.
Construction: An electric motor consists of a rotating rectangular coil ABCD placed between the two poles of a permanent magnet. The two conducting stationary brushes X and Y are kept pressed separately on the slip rings P and Q, respectively. These two rings are attached to an axle (the axle can be rotated mechanically). The outer ends of the two brushes are connected to the battery for the flow of current in the given circuit.

Working: let the current flow through the coil ABCD. By applying Flemings' left-hand rule, an electric current is set up in the winding. Permanent magnets provide the magnetic field. In this case, current-carrying armature conductors experience a force due to the magnetic field, according to the principle stated above.

The Commutator is made segmented to achieve unidirectional torque. Otherwise, the direction of force would have reversed whenever the direction of movement of the conductor is reversed in the magnetic field.

Explain the principle and working of electric motor, by drawing its labelled diagram.

Important Questions on Electricity

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