Transformers - Technical MCQs

Q1:

What is the power dissipated in the primary of the transformer in the given circuit?

A 25 mW

B 500 mW

C 12.5 W

D 62.5 W

ANS:D - 62.5 W

A simple explanation - primary power equal to secondary power in a transformer. Assuming this holds, then.

V2 = 50 * 5 = 250 V.
P2 = V**2 / R = 62.5 W.

For a transformer, the AC voltage & current could be different but power remain equal.