Question

Part A. According to Faraday’s Law, an emf can be formed by

A. a changing electric field

B. a changing magnetic field

C. a constant electric field

D. a constant magnetic field

I think it might be B, idk.

Part B. You are facing a copper ring and insert a magnetic, north first, into the ring. Which direction is the induced current in the ring.

A. Counterclockwise

B. Clockwise

Answer 1

Part A:- Faraday's law says that an emf is induced on account of changing magnetic flux through a coil. Since magnetic flux arises from magnetic field, so option (B) is correct.

Part B:- As the north pole enters the ring, magnetic field increases into the ring. Now, according to Lenz's law, a current must be induced to oppose this changing field. Since the original field is increasing into the coil, the induced field due to the current must be in opposite direction, i.e, out of the ring. For this, the current must Counterclockwise, following Right Hand Rule. So, option (A) is correct.