Question

The coil is rotated through an angle of 90° in 2.0 second. Calculate the magnitude of the average e.m.f. induced in the coil while it is being rotated.

Answer 1

$E=|\frac{d\Phi}{dt}|=\frac{\Delta\Phi}{\Delta t}=\frac{1}{2}\Delta\Phi$

Assume that $\Delta\Phi=8\ (Wb)$. Then

$E=\frac{1}{2}\cdot8=4\ (V)$ . Answer