Question

With the help of diagram, explain basic construction and working principle of a transformer.

Hint:

Transformers transfer electrical energy between circuits via electromagnetic induction without changing frequency.

Answer 1

Basic Construction: A transformer consists of two coils of insulated wire called the primary winding and the secondary winding, wound on a laminated soft iron core. The core provides a path for the magnetic flux.

Working Principle: The transformer operates on the principle of mutual induction:
When an alternating voltage is applied to the primary winding, an alternating current flows through it, producing an alternating magnetic flux in the iron core.
This alternating magnetic flux links with the secondary winding, inducing an alternating electromotive force (EMF) or voltage in the secondary coil according to Faraday’s law of electromagnetic induction.
Depending on the number of turns in the primary and secondary coils, the voltage is either stepped up or stepped down. Mathematically, the voltage ratio is given by: [ fracVsVp = fracNsNp ] where (Vs), (Vp) are the secondary and primary voltages, and (Ns), (Np) are the number of turns on secondary and primary coils respectively.