Question

A rectangular coil (Dimension $5\, cm \times 2.5 \,cm$) with $100\, turns$, carrying a current of $3\, A$ in the clock-wise direction is kept centered at the origin and in the $X-Z$ plane. A magnetic field of $1\, T$ is applied along X-axis. If the coil is tilted through $45^\circ$ about Z-axis, then the torque on the coil is :

• A. 0.55 Nm
• B. 0.27 Nm
• C. 0.38 Nm
• D. 0.42 Nm

Answer 1

Answer: (B)

$|\vec{\tau}| = |\vec{M} \times \vec{B}|$
$\tau = NI \times A \times B \times sin 45^{\circ}$
$\tau \, \, = 0.27 Nm$
Option (2)