A rectangular coil having 200 turns and size `0.30 xx 0.05 m^2` is placed perpendicular to a magnetic field. The field changes from `5x10^(-3)` `Wbm^(-2)`to `2x10(-3)` `Wbm(-2)` in the time interval of 3 millisecond. Calculate the e.m.f. induced in the coil. If the resistance of the coil is `15Omega`, find the value of current flowing through it.

Explanation

`N=200`
`A=0 cdot 30 xx0 cdot 05 m^(2)`
`=1 cdot 5 xx10^(-2)m^(2)`
`B_(1)=5xx10^(-3)" wbm"^(-2)`
`B_(2)=2xx10^(-3)" wbm"^(-2)`
`dt=3 ms =3xx10^(-3) s`
`R =15 Omega`
Induced emf =e= ?
Current `=I=?`
`e=(N(B_(2)-B_(1))A cos 0^(@))/(dt)`
`=(200(2xx10^(-3)-5xx10^(-3))xx1 cdot 5 xx 10^(-2) xx1)/(3xx10^(-3))`
`=(200xx3xx10^(-3)xx1 cdot 5 xx10^(-2))/(3xx10^(-3))`
e=3 volt
`I=(e)/(R) =(3)/(15)=0 cdot 2 A`