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-
Answer & explanation
Correct answer: option 2
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