A bar magnet of length `10cm` and having the pole strength equal to `10^(-3)` weber is kept in a magnetic field having magnetic induction (B) equal to `4pixx10^(-3)` Tesla. It makes an angle of `30^(@)` with the direction of mwgnetic induction. The value of the torque acting on the magnet is
`(mu_(0)=4pixx10^(-7) weber//ampxxm)`

Options

A. `2pixx10^(-7)Nxxm`
B. `2pixx10^(-5)Nxxm`
C. `0.5Nxxm`
D. `0.5xx10^(2)Nxxm`

Answer

a

Explanation

(a) Touque `tau=MB_(H)sin theta`
`=0.1xx10^(-3)xx4pixx10^(-3)xxsin 30^(@)=10^(-7)xx4pixx(1)/(2)`
`=2pixx10^(-7)Mxxm`