Login/Sign Up
A short bar magnet placed with its axis at 30° with a uniform external magnetic field of 0.25 T experiences a torque of magnitude equal to 4.5×10-2J. What is the magnitude of the magnetic moment of the magnet?
A short bar magnet placed with its axis at 30° with a uniform external magnetic field of 0.25 T experiences a torque of magnitude equal to 4.5×10-2J. What is the magnitude of the magnetic moment of the magnet?
CBSE | Class 12 | Magnetism and Matter | NCERT | Physics
A short bar magnet placed with its axis at 30° with a uniform external magnetic field of 0.25 T experiences a torque of magnitude equal to 4.5×10-2J. What is the magnitude of the magnetic moment of the magnet?

Answer –

We are given the magnetic field strength, B = 0.25 T

Torque on the bar magnet is given by, T = 4.5×10-2J

Θ = 30° is the angle between the external magnetic field and  the bar magnet

Torque is related to magnetic moment (M) by the relation-

\[T=MB\sin \theta \]

\[\therefore M=\frac{T}{B\sin \theta }=\frac{4.5\times {{10}^{-2}}}{0.25\times \sin \theta }\]

Hence, the magnetic field is given by –       

\[M=0.36J{{T}^{-1}}\]

i

More Material