Q. A wire loop is rotated in a magnetic field. The frequency of change of direction of the induced e.m.f. is -
A) once per revolution
B) twice per revolution
C) four times per revolution
D) six times per revolution
Explanation
[Solution from source] The induced emf in a rotating loop is e = NBAω sin ωt, which changes sign twice in each full rotation (at 0 and π). So the direction reverses twice per revolution. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.