A rectangular coil of turns `500` and area `2cmxx1cm` carries `100mA` current. It is suspended in a uniform magnetic field of `10^-3T`, so that its plane makes an angle `60^@` with it. The torque on the coil in N-m is

Options

A. `6.0 xx 10^(-4)` Nm
B. `6.0 xx 10^(-5)` Nm
C. `1.2 xx 10^(-3)` Nm
D. 6.0 Nm

Answer

A

Explanation

`tau = MB sin theta = N I A B sin (90^(@) - 60^(@))`
`= 10 xx 1 xx (2 xx 3 xx 10^(-4)) xx 0.2 xx (1)/(2)`
`= 6 xx 10^(-4)` Nm.