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. 0.02V
B. 2V
C. 0.2V
D. `2 xx 10^(-3) V`

Answer

A

Explanation

Here `N = 800, A = 0.05m^2`
`B = 5 xx 10^(-5) T, Delta t = 0.1 s`
induced emf , `epsi = -(Delta phi)/(Delta t )= - ((phi_f - phi_i))/(Delta t)`
`phi_i = N (vecB.vecA) = 800 xx 5 xx 10^(-5) xx 0.05 xx cos 0^@`
`= 2 xx 10^(-3) T m^2`
`phi_f = 0`
` therefore epsi = (-(0-2 xx 10^(-3)))/(0.01) = 2 xx 10^(-2) V = 0.02V`