PhysicsNEET 2021Torque on a current loop, moving-coil galvanometer

Moving Charges and Magnetism

A uniform conducting wire of length $12 a$ and resistance $R$ is wound up as a current-carrying coil in the shape of (i) an equilateral triangle of side $a$ , (ii) a square of side $a$ . The magnetic dipole moments of the coil in each case respectively are:

A. $3 I a^{2}$ and $3 I a^{2}$ ✓
B. $3 I a^{2}$ and $I a^{2}$
C. $3 I a^{2}$ and $4 I a^{2}$
D. $4 I a^{2}$ and $3 I a^{2}$

You have the answer. The worked solution — and why the other three were written — is part of a paid pack.

Moving Charges and Magnetism

More from this chapter in past papers