Given figures show a plane coil moving with velocity \( v \) with respect to N-pole of a bar magnet. The correct interpretation of induced current is given in figure:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3)
By Lenz's law the induced current always opposes the change that produces it. When the coil moves towards the N-pole, the flux through it increases, so the induced current makes the face of the coil nearer the magnet a north pole, which repels the approaching magnet.
A face behaves as a north pole when the current in it appears anticlockwise as seen from that side. Figure (C) shows the coil moving towards the N-pole with the current in this sense, so it gives the correct interpretation.
NCERT (2026-27):
Lenz’s Law and Conservation of Energy – “… The polarity of induced emf is such that it tends to produce a current which opposes the change in magnetic flux that produced it. … As the North-pole of the bar magnet moves towards the coil, the magnetic flux through the coil increases. Hence current is induced in the coil in such a direction that it opposes the increase in flux. This is possible only if the current in the coil is in a counter-clockwise direction with respect to an observer situated on the side of the magnet.”