Question

On what principle electric motor works?
A. Principle of force experienced by current carrying conductor in magnetic field
B. Principle of current experienced by current carrying conductor in magnetic field
C. Principle of force experienced by current carrying conductor in electric field
D. None of the above

Answer 1

Hint: 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 a magnetic field which experiences a force.

Complete step by step answer:
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 experiment shows that the magnitude of the force depends directly on the current in the wire, and the strength of the magnetic field. The force is greatest when the magnetic field is perpendicular to the conductor.

So, an electric motor is based on the principle of ‘force experienced by a current carrying conductor in a magnetic field’.
Hence, the correct option is A, i.e., Principle of force experienced by the current carrying conductor in the magnetic field.

Additional Information:
When an electric current is passed through a rectangular coil, this current produces a magnetic field around the coil. Thereafter the magnetic field of the magnet interacts with the magnetic field of the coil and causes the coil to rotate continuously.

Note: The students should understand that the working of the electric motor is purely based on the 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.