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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.
Solution
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
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