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Magnetism And Matter

Question
CBSEENPH12037807

Define magnetic dipole moment of a magnet and write its unit by taking into consideration the torque acting on it, when placed in magnetic field. Is it a vector or a scalar?

Solution
Torque acting on a dipole, τ = MB sin θ 

If, B = 1 and θ = 90°,then
                     M = τ 

Magnetic dipole moment is numerically equal to the torque experienced by the magnet when placed perpendicular to a uniform magnetic field of unit strength.
i.e.,  M = τB sin θ. 
So, SI unit of M is N m T-1 

Magnetic dipole moment is a vector.