Question

Define the dipole moment of a magnetic dipole. Write its S.I. unit.
Obtain the expression for the torque acting on a magnetic dipole placed in an external unifrom magnetic field.

Answer 1

Magnetic dipole moment is a product of current flowing through the coil and area . S.I is Am²  

`τ = F_1 a/2 sin theta + F_2 a/2 sin theta `

= I ab B sin θ

= I A B sin θ

m = I A 

τ = m × B