A circular loop of area 1cm^2 carrying a current of 10 A is placed in a magnetic field of  2 T….

Q: A circular loop of area 1cm^2 carrying a current of 10 A is placed in a magnetic field of  $2 T \hat{j}$ . The loop is in XY plane with current in clock wise direction. Find the torque on the loop .

Sol: $\large \vec{\tau} = \vec{M} \times \vec{B}$

$\large \vec{\tau} = n i\vec{A} \times \vec{B}$

$\large \vec{\tau} = 10 \times 10^{-4} (-\hat{k}) \times 2 \hat{j}$

$\large = 2 \times 10^{-3} N m \hat{i} $