Question

Explain the construction and working of an electric motor.

Answer 1

The electric motor is an electrical device, which is capable of converting electrical energy into mechanical energy by using the magnetic effect of electric current. In an electric motor, we place a current-carrying-conductor in the magnetic field which experiences a force.

Complete step-by-step solution:
An electric motor is an electrical device, which is used for converting electrical energy into mechanical energy (usually a torque). This conversion is obtained through the generation of a magnetic field.
When a current-carrying conductor is placed in a magnetic field, it experiences a force.
The figure given below shows us the construction of an electric motor. In the electric motor, we have a current-carrying coil which is placed between the north-south poles of a powerful magnet. When we allow the current to flow through this coil, the coil will experience a force since it is placed in a magnetic field. The direction of this force is given by Fleming’s left-hand rule. This force leads to rotation of the coil in the magnetic field which is the required mechanical energy, which gets from the electric motor.
When we perform this experiment in the laboratory then it is observed that the magnitude of the force acting on the coil is directly proportional to the current flowing through the wire, and also the strength of the magnetic field due to the magnets. The force is found to be greatest when the magnetic field is perpendicular to the rotating coil.

Hence, an electric motor converts electrical energy into mechanical energy.

Note: The students should understand that the working of the electric motor is purely based on Faraday’s law of electromagnetic induction where the magnetic effect of electric current is involved. The law states that the changing fields produce electromotive force or emf.