A coil area 100 `cm^(2)` having 500 tums carries a current of 1 mA . It is suspended in a uniform magnetic field of induction `10^(-3) Wb//m^(2)`. Its plane makes an angle of 60° with the lines of induction. Find the torque acting on the coil.

Explanation

Given `i = 1 mA=10^(-3) A, N=500, B=10^(-3)Wb//m^(2)`
`theta=60^(@),tau=?A=100cm^(2)=100xx10^(-4)m^(2)`
Couple acting on the coil is given by
`tau=BiANsinphi,` Where `phi` is angle made by normal to the plane of coil with B. `phi =90 - 60 = 30°`
`thereforeC=10^(-3)xx10^(-3)xx100xx10^(-4)xx500xxsin30`
`=250xx10^(-8)Nm`