A 800 turn coil of effective area `0.05 m^(2)` is kept perpendicular to a magnetic field `5xx10^(-5)` T. When the plane of the coil is rotated by `90^(@)` around any of its coplanar axis in 0.1 s, the emf induced in the coil will be:

Options

A. 0.02 V
B. 2 V
C. 0.2 V
D. `2xx10^(-3)V`

Answer

A

Explanation

`e_("induced")=(-dvarphi)/dt=(-Deltavarphi)/dt`
`varphi_(l)=N(vecB.vecA),varphi_(f)=0`
`varphi_(l)=800xx5xx10^(-5)xx5xx10^(-2)`
`Deltat=0.1`
`e_("induced")=-((0-800xx5xx10^(-5)xx5xx10^(-2)))/0.1=0.02V`