Question

The armature of a small generator consists of a flat, square coil with 120 turns and sides
with a length of 1.6 cm. The coil rotates in a magnetic field of 0.075T. What is the
angular speed of the coil if the maximum emf produced is 24.0mV?

Answer 1

Flux is given by $\phi =BA\cos\omega t$ $instantaneous\ emf = e(t) = - N d(\phi)/dt = - Nw (BA) [- sin wt]$

maximum emf= $NwBA$

$0.024=120\times w\times0.075\times0.016^2\\w=10.41rad/sec$