The working principle of an electric motor is based on the interaction between a magnetic field and electric current. When an electric current flows through a conductor (like a wire), it creates a magnetic field around the conductor. If this conductor is placed within an external magnetic field, the two magnetic fields interact, creating a force that causes movement. This force is known as the Lorentz force, and it is the core principle behind the operation of an electric motor.
An electric motor consists of two main parts: the stator and the rotor. The stator is the stationary part, usually consisting of magnets or electromagnets that produce a magnetic field. The rotor is the rotating part, typically a coil of wire, that is placed inside the magnetic field generated by the stator. When electric current flows through the rotor, it creates its own magnetic field. The interaction between the rotor’s magnetic field and the stator’s magnetic field generates a force that makes the rotor spin.
In DC motors, the direction of the current is reversed periodically using a commutator, ensuring continuous rotation. The commutator acts as a switch, reversing the current direction every half-turn to maintain the direction of rotation. In AC motors, the current alternates automatically, causing the rotor to rotate continuously without the need for a commutator.
The strength of the magnetic field, the amount of current, and the design of the rotor determine the motor’s speed and torque. Electric motors are efficient and versatile devices that convert electrical energy into mechanical motion. They are used in countless applications, from household appliances like fans and washing machines to industrial machinery and electric vehicles.