Home › Karnataka PUC II › Physics › Magnetism and Matter › The work required to rotate a magnetic dipole of…
The work required to rotate a magnetic dipole of moment m in a field B from θ = 0 to θ = 180° is
A2mB
B0
CmB
D−mB
Answer & Solution
Correct answer: A. 2mB
W = ΔU = (−mB cos 180°) − (−mB cos 0°) = mB − (−mB) = 2mB. Work is positive because we move from minimum to maximum potential energy.
Related questions
Substances holding ferromagnetism for a long time are:Above the Curie temperature a ferromagnet turns into:Alnico is an alloy of iron, aluminium, nickel, cobalt and:Ferromagnets keeping their magnetisation afterwards are called:Substances that get strongly magnetised in a field are:Substances that get weakly magnetised in a field are:Substances pushed away from a strong magnetic field are:Declination, dip and the horizontal component are called the: