A conducting looop of area `5.0cm^(2)` is placed in a magnetic field which varies sinusoidally with time as `B=0.2sin300t` . The normal to the coil makes an angle of `60^(@)` with the field. The emf induced at `t=(pi//900)s`

Options

A. `7.5xx10^(-3)V`
B. zero
C. `15xx10^(-3)V`
D. `20xx10^(-3)V`

Answer

A

Explanation

`phi=Bacostheta=0.2sin(300t)xx5xx10^(-4)xxcos60^(@)`
`=5xx10^(-5)sin(300t)`
`e=(dphi)/(dt)=5xx10^(-5)xx3000cos(300t)`
`=1.5xx10^(-2)cos((300xx(pi)/(900))`
`=1.5xx10^(-2)cos(pi//3)=0.75xx10^(-2)=7.5xx10^(-3)V` .