Question

A rectangular coil of copper wires is rotated in a magnetic field. The direction of the induced current changes once in each

• A. two revolutions
• B. one revolution
• C. half revolution
• D. one-fourth revolution

Answer 1

The correct option is C half revolution

We know that the emf induced is given by:-

$E=n\omega BA\cos \omega t$

Hence, after every half time period, E will change its sign.

Hence, after each half revolution, induced current will change its direction.