Question

A square coil and a rectangular coil are each made from the same length of wire. Each contains a single turn. The long sides of the rectangle are twice as long as the short sides. Find the ratio τ_square /τ_rectangle of the maximum torques that these coils experience in the same magnetic field when they contain the same current.

Answer 1

The torque acting on the coil is, For maximum torque we have θ-90° and for a single turn of the coil we have, τ-MLAB sin 900 - IAB

will be proportional to the For a given magnetic field and for a given current, the torque area of the coil. Thus the ratio of maximum torque for a square to the ratio of maximum torque for a rectangle is, square rectangle ctangle 4 6 3 16 18 9