Find the e.m.f. induced in a coil of 100 turns and crosssectional area `0.4 m^2`, when a magnetic field perpendicular to a plane of the coil changes from `0.5 Wbm^(-2)` to `0.1Wbm(-2)` at a uniform rate over a period of 0.04 s. If the resistance of the coil is `3.2kOmega`, find the value of current flowing through it.

Explanation

Induced emft=e= ?
Number of turns =N=100
`A=0 cdot 4 m^(-2)`
`B_(1)=0 cdot "wbm"^(-2)`
`B_(2)=0 cdot 1" wbm"^(-2)`
`dt =0 cdot 04 s`
`R=3 cdot 2 k Omega =3200 Omega`
`e=(N(B_(2)-B_(1))A cos 0^(@))/(dt)`
`=(100(0 cdot 1 -0 cdot 5)xx0 cdot4)/(0 cdot 04)`
`e=(16)/(0 cdot 04) =400 volt`
Current `=I=(e)/(R) =(400)/(3200)=0 cdot 125` A