Question

In which of the following situations is an electric current NOT produced? a. A magnet moves relative to a stationary wire. b. A wire moves relative to a stationary magnet. c. A wire has been wrapped around a stationary magnet. d. The magnetic field through a loop is decreasing.

Answer 1

Option (c)

Step-by-step explanation:

according to the laws of electromagnetic induction, whenever a magnetic flux linked with a coil changes an induced emf is developed.

In case (a), the magnet is moving relative to stationary wire, that means the magnetic flux changes, hence an induced emf is developed.

In case (b), wire moves relative to stationary magnet that means the magnetic flux changes, hence an induced emf is developed.

In case (c), wire is wrapped around a stationary magnet that means no magnetic flux changes, hence no induced emf is developed.

In case (d), the magnetic field through a loop is decreasing that means the magnetic flux linked changes, hence an emf is induced.

So, no emf is induced in case (c).