A coil in the shape of an equilateral triangle of side l is suspended between the pole pieces of a permanent magnet such that B is in 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

Step-by-step solution

Torque acting on equilateral triangle in a magnetic field B is =i A B Area of triangle LMN A= 3 4 l^2 and =90^ Substituting the given values in the expression for torque, we have aligned & =i 3 4 l^2 B 90^ & = 3 4 i l^2 B ( 90^ =1 ) aligned Hence, l=2 ( 3 B i )^ 1 / 2