Question

A coil of $100$ turns and resistance $100\Omega$ is connected in series with a galvanometer of resistance $100\Omega$ and the coil is placed in a magnetic field. If the magnetic flux linked with the coil changes from ${10}^{-3}Wb$ to $2\times {10}^{-4}Wb$ in a time of $0.1s,$ calculate the induced emf and current.

Answer 1

$\frac{d\varphi }{dt}=\frac{{10}^{-3}-(2\times {10}^{-4})}{0-1}=19000Emf,ϵ=NE=\frac{100\times 8{\times 10}^{-4}}{{10}^{-1}}=800{\times 10}^{-3}=8{\times 10}^{-1}v$

Current, $i=\frac{ϵ}{R_{coil}+R_g}=\frac{8{\times 10}^{-1}}{100+100}=\frac{8}{2}{\times 10}^{-3}=4{\times 10}^{-3}A$