Two wires of equal lengths are bent in the form of two loops. One of the loops is square shaped whereas the other loop is circular. These are suspended in a uniform magnetic field and the same current is passed through them. Which loop will experience greater torque? Give reasons.

Explanation

For the given length, the area enclosed by circular loop is greater than the area enclosed by square shaped loop. The torque acting on a coil or area A, carrying current I suspended into a uniform magnetic field B is, `tau=IBA sin alpha`, i.e., `taupropA`, (for the given value of B and I). Therefore, the torque on circular loop will be more than that on square shaped loop.