Question

In which case is there an induced electromotive force?

A. A permanent bar magnet is held inside a coil of wire
B. Field line's from earths magnetic field cross the area of a coil of wire
C. An electromagnet operating on direct current is held a second coil of wire
D. An electromagnet operating on alternating current is held inside a second coil of wire

Answer 1

I think it's B, that's the only case where something is moving. I'm actually doing the quiz right now lol

Answer 2

An electromagnet operating on alternating current is held inside a second coil of wire. (C)
I just took this test. That is the answer.