Name: An Elementary Study of Domestic Electric Circuits
Uploaded: 2019-07-19
Duration: 5 min 52 s
Description: The electricity we consume is produced through electromagnetic induction at power plants. In this video, we will see the journey of electricity from the powe...

Question

Draw a labelled circuit diagram of a simple electric motor and explain its working. In what way these simple electric motors are different from commercial motors?

Accepted Answer

A simple diagram of an electric motor is given below:

Working of an electric motor:

The arms $A B$ and $C D$ are perpendicular to the direction of the magnetic field. When current flows through the coil, these arms experience the magnetic force. On applying Fleming’s left-hand rule, the force acting on arm $A B$ is downward and on arm $C D$ it acts upwards. Since these two forces are equal in magnitude and opposite in direction, so they form a couple and the torque of the couple rotates the armature in clockwise direction.

After completing half revolution by the armature, the direction of current in arm $A B$ and $C D$ is reversed. Now, arm $A B$ experiences force upward and arm $C D$ in the downward direction. Again the two forces are equal in magnitude and opposite in direction so they form a couple and the torque of the couple rotates the armature in the clockwise direction. Thus, the armature of $D C$ motor rotates in the same direction.

Simple electric motors use permanent magnets whereas a commercial motor uses electromagnets.

Draw a labelled circuit diagram of a simple electric motor and explain its working. In what way these simple electric motors are different from commercial motors?

Important Questions on Magnetic Effects of Electric Current

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