question_answer

Transformer is based upon the principle of:

A) self- induction                  

B)  mutual induction

C) eddy current     

D) none of these

Correct Answer: B

Solution :

Key Idea: Transformer consists of two coils one primary and the other secondary. Transformer is a device based on the principle of mutual induction, which is used for converting large alternating current at low voltage into small current at high voltage and vice-versa. NOTE: 1. The transformer which converts low voltages into higher ones are called step-up transformers, while those which convert high voltages into lower ones are called step-down transformers.   Transformers are used only in AC not DC.