A coil in the shape of an equilateral triangle of side l is suspended between the pole pieces of a permanent magnet such that <img alt="\mathrm{\overrightarrow{B}}" src="https://entrancecorner
A coil in the shape of an equilateral triangle of side l is suspended between the pole pieces of a permanent magnet such that is in the plane of the coil. If due to a current i in the triangle a torque acts on it, the side l of the triangle is