PHYSICS · Multi-part · AP · Physics 2: Algebra-based · Magnetism and Electromagnetism · Magnetism and Electromagnetism
Problem
A rectangular coil used in a small d.c. motor has 50 turns. Each turn has length 6.0 cm and width 4.0 cm. The coil carries a current of 2.5 A and is placed in a uniform magnetic field of 0.25 T.
Consider one of the longer sides of the coil and answer the following:
(i) Calculate the maximum force that can act on this side of the coil.
(ii) The coil is rotated through an angle of 60∘ about its central axis. Calculate the new force on the same side after rotation.
(iii) If the motor is required to maintain the force found in part (i) even after the 60∘ rotation, determine the current that must now be supplied to the coil.