Electrical Engineering XYZ MCQ
The working principle of transformer depends on:
- Ampere’s law
- Newton’s law
- Coulomb’s law
- Faraday’s law of electromagnetic induction
Correct answer: 4. Faraday’s law of electromagnetic induction
Explanation: The working principle of a transformer is based on Faraday’s law of electromagnetic induction. Faraday’s law states that a changing magnetic field induces an electromotive force (EMF) in a coil or conductor. In the case of a transformer, alternating current in one coil (primary coil) produces a changing magnetic field, which, in turn, induces a voltage in another coil (secondary coil) through electromagnetic induction.
Transformers consist of two coils of wire, usually wound around a common magnetic core. When the primary coil is connected to an alternating current (AC) source, it generates a changing magnetic field. This changing magnetic field induces a voltage in the secondary coil according to Faraday’s law. The ratio of the number of turns in the primary coil to the number of turns in the secondary coil determines the voltage transformation in the transformer.
In summary, Faraday’s law of electromagnetic induction is fundamental to the operation of transformers, allowing for the efficient transfer of electrical energy between different voltage levels.