Question

The coil is rotated through an angle of 90° in 0.2 second. Calculate the magnitude of the average e.m.f. induced in the coil while it is being rotated.

Answer 1

$$E=\frac{d\Phi}{dt}=\frac{\Delta\Phi}{\Delta t}=0.5\Delta\Phi$$

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

$$E=0.5(8)=4\ V$$