EasyPhysics
+4 / -1
A uniform magnetic field is restricted within a region of radius r. The magnetic field changes with time at a rate . Loop 1 of radius R > r enclosed the region of magnetic field having radius r and another loop 2 of radius R is outside the region of magnetic field as shown in the figure below. Then the e.m.f generated will be
A
Zero in loop 1 and zero in loop 2
B
-πr² in loop 1 and -πr² in loop 2
C
−πR² in loop 1 and zero in loop 2
D
− πr² in loop 1 and zero in loop 2
Explanation
For loop 1: ε = −dφ/dt = −dB/dt × πr²
For loop 2, the induction can happen due to the induced current in loop 1, which will be much smaller than the induced emf in loop 1. Hence the most suitable option is (4)
Practice Physics Exams
Full-length mock tests with detailed analytics, rank, and percentile.
Browse Exams