A wire of length ' L ' carries a current ' I '. If the wire is turned into a square coil of single turn, the maximum magnitude of the torque in a given magnetic field ( B ) is

Step-by-step solution

Maximum torque on a square coil The magnetic dipole moment determines the torque experienced by a current-carrying loop in a magnetic field. Using a wire of length L , the side length of the square coil is a = L 4 , giving an area A = a^2 = L^2 16 . For a single-turn coil, the magnetic dipole moment is M = IA = IL^2 16 . The torque magnitude is = MB , which reaches its maximum _ max = MB when = 1 . Therefore, _ max = IBL^2 16 . This result corresponds to option D.