Question

19. There are two coils A and B as shown in figure. A current
starts flowing in B as shown when A is moved towards B
and stops. when A stops moving, The current in A is courter
clockwise. B is kept stationary when A moves. We can infer
that
(a) There is a constant current in the clockwise direction in A
(b) There is a varying current in A
(c) There is no current in A
(d) There is a constant current in the counter clockwise
direction in A
B​

Answer 1

Answer:

there is a varying current in A

Answer 2

We can infer that there is varying current in A. That is because of the following reasons:

• When a coil is placed in a moving magnetic field current is produced in  the conductor. This is based on Faraday's law of electro magnetic induction.
• Faraday's law of electromagnetic induction states that"when a coil is placed in a moving magnetic field current is produced in the coil."
• so according to this law if current is induced in coil B then coil a must have a varying current flowing through it.
• If and only if there is a varying current flowing through a it produces a magnetic field that is varying.
• So when the coil A is moving it induces current in coil B as per Faraday's law.