A rectangular coil of 200 turns has length and breadth
PHYSICS · Multi-part · AP · Physics C: Electricity and Magnetism · Magnetic Fields and Electromagnetism · Magnetic Fields and Electromagnetism
Problem
A rectangular coil of 200 turns has length 5cm and breadth 3cm. It is free to rotate about a central axis and is placed in a uniform magnetic field of 0.20T. The plane of the coil is initially parallel to the magnetic field lines. The coil carries a current of 0.50A.
(i) Calculate the magnitude of the couple (torque) acting on the coil in this position.
(ii) If the current in the coil is doubled while all other factors remain unchanged, what qualitative change, if any, would you expect in the speed of rotation of the motor? Give reason for your answer.