An electric motor works on the principle of ________.
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Lorentz's Law
An electric motor turns electrical energy into mechanical energy. It works because a current-carrying conductor placed in a magnetic field experiences a force; on the two sides of the motor's coil the forces act in opposite directions and turn it. This force on moving charges in a magnetic field is the Lorentz force, and its direction is given by Fleming's left-hand rule.
Why the other options are incorrect
Option (1) Faraday's Law — Incorrect. It says a changing magnetic field induces a current, the principle of the electric generator.
Option (3) Lenz's Law — Incorrect. It gives the direction of an induced current: it always opposes the change that produces it.
Option (4) Ohm's Law — Incorrect. It relates the current, voltage and resistance of a conductor, \(V=IR\).