Question

Name some devices in which electric motors are used.

Answer 1

Hint: Electric motors are used in almost every home appliance we use in our daily activities. They are the main components in most of the appliances as they convert the incoming electric energy into the mechanical energy required for the device.

Complete answer:
Electric motor is the converter of the electrical energy to the required mechanical energy in any device. The electronic devices such as water pumps, fans, refrigerators, mixer grinders and other appliances use electric motors to function. Electric motor uses the electric energy to rotate a metal strip by using the magnetic properties of flowing alternating current.
 

The above figure describes the working of an electric motor using an alternating source. A metal strip is wounded by the wire through which the current is passing. The alternating current passing through the wire wound around the metal acts as a solenoid with the core. As a result, a magnetic field is formed on the metal strip which changes its direction as the AC current changes its direction. What happens when this coil is kept in a strong external magnetic field?
The answer to this question is the working principle of the electric motor. When the face of the strip with the North pole faces the North pole of the setup, a repulsive force comes into play. Since the metal strip is pivoted about its axis passing through the center the only option it gas is to rotate and face the other side. Thus, we have seen that a rotation has initiated. Now, we should remember that the power supply changes its direction, i.e., all of a sudden the North pole of the metal strip becomes South and vice versa. This retains the rotation as long as the power supply is on. Thus the electric motor keeps rotating.
We can employ this phenomenon in devices by making use of the rotation as the required mechanical energy in the device.

Note:
When Direct current is used instead of Alternating current the direction of the current has to be changed manually using a commutator – a ring with two gaps - which allows the change of direction of electric current thus the magnetic field. We don’t use DC in households.
The curved magnets used in the motor enhances the efficiency of the system.