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 0.05 Nm. The magnitude of the magnetic moment of the magnet is

Question

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 0.05 Nm. The magnitude of the magnetic moment of the magnet is (A) 0.2 J T-1 (B) 0.4 J T-1 (C) 4.0 J T-1 (D) 0.64 J T-1

Tardigrade Admin · Accepted Answer

τ = MB sin θ M= (τ/B× sinθ)=(0.05×2/0.25)=0.4 JT-1

Q. A short bar magnet placed with its axis at $3 0^{\circ}$ with a uniform external magnetic field of $0.25 T$ experiences a torque of magnitude equal to $0.05 N m$ . The magnitude of the magnetic moment of the magnet is

$0.2 J T^{- 1}$

$0.4 J T^{- 1}$

$4.0 J T^{- 1}$

$0.64 J T^{- 1}$

$τ = MB s in θ$
$M = \frac{τ}{B \times s in θ} = \frac{0.05 \times 2}{0.25} = 0.4 J T^{- 1}$

Q. A short bar magnet placed with its axis at 30∘ with a uniform external magnetic field of 0.25T experiences a torque of magnitude equal to 0.05Nm. The magnitude of the magnetic moment of the magnet is

0.2JT−1

0.4JT−1

4.0JT−1

0.64JT−1