Question

A magnet of magnetic moment $50\hat{i}A-m^2$ is placed along x- axis in a magnetic field$\overrightarrow{B}=(0.5\hat{i}+3.0\hat{j})$ tesla. The torque acting on the magnet is

• A. $175\hat{k}N-m$
• B. $75\hat{k}N-m$
• C. $150\hat{k}N-m$
• D. $25\sqrt{37}\hat{k}N-m$

Answer 1

The correct option is C $150\hat{k}N-m$

Given,

Magnetic field $\overrightarrow{B}=0.5\hat{i}+3.0\hat{j}T$

Magnetic moment $\mu =50\hat{i}A{m}^2$

Torque on magnet $\tau$

$\tau =\mu \times \overrightarrow{B}=50\hat{i}\times (0.5\hat{i}+3.0\hat{j})$

$\tau =150\hat{k}N-m$

Hence, Torque experiences by the magnet present in the magnetic field, $\tau =150\hat{k}N-m$