A magnet of dipole moment m is aligned in equilibrium position in a magnetic field of intensity B. The work done to rotate it through an angle θ in the magnetic field is

Question

A magnet of dipole moment m is aligned in equilibrium position in a magnetic field of intensity B. The work done to rotate it through an angle θ in the magnetic field is (A) m B sin θ (B) m B cos θ (C) m B(1- cos θ) (D) m B(1- sin θ)

Tardigrade Admin · Accepted Answer

Work done W=∫ limits0θ m B sin θ d θ=m B(1- cos θ) ( text as Δ W=τ d θ=m B sin θ d θ)

Q. A magnet of dipole moment $m$ is aligned in equilibrium position in a magnetic field of intensity $B$ . The work done to rotate it through an angle $θ$ in the magnetic field is

$m B sin θ$

$m B cos θ$

$m B (1 - cos θ)$

$m B (1 - sin θ)$

Work done $W = 0 \int θ m B sin θ d θ = m B (1 - cos θ)$
$(as Δ W = τ d θ = m B sin θ d θ)$

Q. A magnet of dipole moment m is aligned in equilibrium position in a magnetic field of intensity B. The work done to rotate it through an angle θ in the magnetic field is

mBsinθ

mBcosθ

mB(1−cosθ)

mB(1−sinθ)