Question

A certain coil of wire consists of 500 circular loops of radius 4cm, it is placed between poles of large electromagnet when the electromagnetic field is uniform perpendicular to the plane or coil and increasing at the rate of 0.2Telsa per second. What is the magnitude of the resulting emf?

Answer 1

Number of loops, $N=500$

Radius of loop, $r=4\space cm=4\times10^{-2}\space m$

Area of cross-section, $A={\pi r^2}=$$3.14\times(4\times 10^{-2})^{2}=5.024\times10^{-3}\ m^{2}$

flux per unit time, $\dfrac{d\phi}{dt}=0.2\space tesla/second$

$resulting\space emf=N\dfrac{d\phi}{dt}\times A$ $=500\times0.2\times5.024\times10^{-3}=0.5024\ Volts$