Question

A coil of 50 turns is pulled in 0.02s from between the poles of a magnet, where each of its turn is linked with magnetic flux of $31\times {10}^{-6}Wb$ to a place where the lined flux is $1\times {10}^{-6}Wb$ per turn. The average e.m.f is induced is

• A. $7.5\times {10}^{-2}V$
• B. $7.5\times {10}^{-3}V$
• C. Zero
• D. $7.5\times {10}^{-4}V$

Answer 1

The correct option is A $7.5\times {10}^{-2}V$

$Inducedemfaccordingtofaradayslawv=-N\frac{d\varphi }{dt}N=no.ofturnsand\varphi =fluxlinkedNowv=-N\Delta \varphi /\Delta tv=-\frac{50\times (1\times {10}^{-6}-31\times {10}^{-6})}{0.02}=7.5\times {10}^{-2}V$