A rectangular coil carrying current I is placed in a uniform magnetic field B such that the direction of B is perpendicular to the plane of the coil. Calculate the torque experienced by the coil.

Explanation

Torque acting on the coil,
`tau=BIA sin theta`
Where I= current in the coil, A= area of the coil and `theta` is the angle between the magnetic field and the normal to the surface of the coil.
As the coil placed perpendicular to the direction of B,the normal to its surface is parallel to B, i.e., `theta=0`. Hence `theta=0`.
`:. tau=BIA*0=0`
Therefore no torque act on the coil.