The magnetic flux through a coil perpendicular to its plane and directed into paper is varying according to the relation `phi=(2t^(2)+4t+6)mWb`. The emf induced in the loop at t=4 s is

Options

A. 0.12 V
B. 2.4 V
C. 0.02 V
D. 1.2 V

Answer

C

Explanation

Given, `phi=(2t^(2)+4t+6)mWb`
AS, `epsi=(dphi)/(dt)=(d)/(dt)(2t^(2)+4t+6)xx10^(-3)Wbs^(-1)`
`=(4t+4)xx10^(-3)V`
At `t=4s`
`epsi=(4xx4+4)xx10^(-3)V=20xx10^(-3)=0.02V`