Question

What can produce an electric current in a closed coil?

Options

• A continuously pressed key with no change in current

• A stationary magnet with no changing magnetic flux

• A steady magnetic field with both coils stationary

• A time-varying magnetic field

Answer 1

A closed coil can have an induced electric current when it is subjected to a time-varying magnetic field. Induction occurs when the magnetic flux through the coil changes.