Give the expression for torque acting on a magnetic dipole placed in an uniform magnetic field and give the meaning of the symbols.

Explanation

The torque acting on a magnetic dipole ( magnetic needle ) is given by `vectau = vecm xx vecB` .
Note : `|vectau| = "m B" sin theta" ""where"" " theta ` is the angle between `vecm " ""and"" " vecB` and m = magnetic moment.