A bar magnet having a magnetic movement of $2 imes 10^4 \mathrm{JT}^{-1}$ is free to rotate in a horizontal plane. A horizontal magnetic field $B=6 imes 10^{-4}$ $T$ exists in the space. The work done in taking the magnet slowly from a direction parallel to the field to a direction…

Question

A bar magnet having a magnetic movement of $2 	imes 10^4 \mathrm{JT}^{-1}$ is free to rotate in a horizontal plane. A horizontal magnetic field $B=6 	imes 10^{-4}$ $T$ exists in the space. The work done in taking the magnet slowly from a direction parallel to the field to a direction $60^{\circ}$ from the field is :

Aicharya · Accepted Answer

$\begin{aligned} \mathrm{W} & =\mathrm{MB}\left(\cos 	heta_1-\cos 	heta_2ight) \ & =2 	imes 10^4 	imes 6 	imes 10^{-4}\left(\cos 	heta-\cos 60^{\circ}ight) \ & =12 	imes \frac{1}{2}=6 \mathrm{~J} \end{aligned}$

A bar magnet having a magnetic movement of $2 \times 10^4 \mathrm{JT}^{-1}$ is free to rotate in a…

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