A circular loop of area $0.01\, m^2$ carrying a current of 10 A, is held in a magnetic field of 0.1 T parallel to the plane of the loop. The torque acting on the loop is-

0.01 N m

The correct answer is Option (2) → 0.01 N m

Torque on a current loop: $\tau = n I A B \sin\theta$

Given: $n = 1$, $I = 10 \ \text{A}$, $A = 0.01 \ \text{m}^2$, $B = 0.1 \ \text{T}$, $\theta = 90^\circ$ (field parallel to plane → angle between normal and B is 90°)

Torque:

$\tau = 1 \cdot 10 \cdot 0.01 \cdot 0.1 \cdot \sin 90^\circ$

$\tau = 0.01 \ \text{Nm}$

Torque acting on the loop = 0.01 Nm