A magnetic dipole of moment is held in a uniform magnetic field of magnitude
PHYSICS · Multi-part · CBSE · Physics · Magnetism and Matter · Magnetism and Matter
Problem
A magnetic dipole of moment μ is held in a uniform magnetic field of magnitude B. The dipole axis makes an angle θ with the field direction.
(i) Write the mathematical expression for the potential energy of the dipole in the field, clearly defining each symbol used.
(ii) Draw a neat, labelled graph showing the variation of the potential energy with θ for 0≤θ≤2π.
(iii) From the graph, identify the orientations that correspond to stable and unstable equilibrium. Give a reason for each.
(iv) Explain, with reference to the expression obtained in (i), why the dipole tends to rotate towards the position of stable equilibrium when slightly disturbed.