Question

Two wires of equal length are bent in the form of two loops. One of the loops is square shaped whereas the other loop is circular. These are suspended in a uniform magnetic field and the same current is passed through them. Which loop will experience greater torque? Give reasons.

Answer 1

Torque τ = IAB sin θ ∝ A. For given perimeter the area of circular loop is maximum, so a circular loop will experience greater torque.