Question

A 50 loop circular coil has a radius of 3cm .it is oriented so that the field lines of a magnetic field are normal to the area of the coil .if the magnetic field is varied so that vector B increase from 0.10T to 0.35T in 2milliseconds,what is the average induced emf in the coil?

Answer 1

$$\epsilon=NA\frac{B_f-B_i}{t}=\pi r^2N\frac{B_f-B_i}{t}$$

$$\epsilon=\pi (0.03)^2(50)\frac{0.35-0.1}{0.002}=18\ V$$