PGLAW 2019 Panjab University Entrance Exam With Answers

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27.

Electric Motor Works On The Principle Of

A: Newton's law
B: Ohm's Law
C: Electromagnetic Induction
D: Darwin's Theory

The answer is: C

Explanation

An electric motor works on the principle of C: Electromagnetic Induction.

An electric motor is a device that converts electrical energy into mechanical energy. It works on the principle of the interaction between a magnetic field and an electric current. The motor consists of a coil of wire (called an armature) that is placed between the poles of a permanent magnet. When an electric current flows through the coil, it generates a magnetic field that interacts with the magnetic field of the permanent magnet. The interaction between these magnetic fields causes a torque or rotational force to be exerted on the armature, causing it to rotate. This rotational motion is transferred to the mechanical system that the motor is connected to, such as a fan or a car's wheels. The principle of electromagnetic induction was discovered by Michael Faraday in the early 19th century and forms the basis of many electrical devices, including electric motors and generators.