Question

An emf is produced in a coil, which is not connected to an external voltage source. This can be due to
A. the coil being in a time-varying magnetic field
B. the coil moving in a time-varying magnetic field
C. the coil moving in a constant magnetic field
D. the coil is stationary in external spatially varying magnetic field, which does not change with time

Answer 1

Correct Answer - A::B::C
When a coil is not connected to an external source of voltage, then emf in the coil is produced due to changing magnetic flux with time, `e=-(dphi)/(dt)`