Question

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

Answer 1

1. An electric motor is a device that converts electric energy into mechanical energy.
2. The electric motor works on the basic principle of electromagnetism.
3. There is a magnetic field produced around a wire when a current is passed through it.
4. This current-carrying wire has moving charges flowing through it.
5. This moving charge interacts with the external magnetic force present in the surrounding.
6. There is a Lorentz force on the electric charge, thereby producing a force on the whole electric wire.
7. The force is given by the equation $F=IL\times B$ where I is current, L is the length of wire, and B is the external magnetic field.
8. The interaction produces a force on the wire.
9. The force is such that it produces a torque on the loop causing it to rotate.
10. Given below is a labeled diagram of an electric motor.

Commercial motors:

1. Commercial motors used electromagnets instead of a permanent magnet.
2. Commercial magnets have more number of turns of the conducting coil.
3. A soft iron core is present in commercial magnets.