154071 A bar magnet having a magnetic movement of $2 \times 10^{4} \mathrm{~J} \mathrm{~T}^{-1}$ is free to rotate in a horizontal plane. A horizontal magnetic field $B=6 \times 10^{-4}$ $T$ 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
154071 A bar magnet having a magnetic movement of $2 \times 10^{4} \mathrm{~J} \mathrm{~T}^{-1}$ is free to rotate in a horizontal plane. A horizontal magnetic field $B=6 \times 10^{-4}$ $T$ 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
154071 A bar magnet having a magnetic movement of $2 \times 10^{4} \mathrm{~J} \mathrm{~T}^{-1}$ is free to rotate in a horizontal plane. A horizontal magnetic field $B=6 \times 10^{-4}$ $T$ 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
154071 A bar magnet having a magnetic movement of $2 \times 10^{4} \mathrm{~J} \mathrm{~T}^{-1}$ is free to rotate in a horizontal plane. A horizontal magnetic field $B=6 \times 10^{-4}$ $T$ 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