A circular coil made up of copper, is placed on a table top. Magnetic field is normally outwards. Now, the magnetic field is gradually decrease. The direction of induced current as seen from the top side is
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Anti clock wise
By Lenz's law the induced current opposes the change in magnetic flux that produces it.
The field points outwards (upwards, towards an observer looking from the top) and is decreasing, so the outward flux through the coil decreases. To oppose this decrease, the induced current must produce an outward field inside the coil.
A current that produces a field towards the observer appears anticlockwise to that observer. So the induced current is anticlockwise as seen from the top.
Why the other options are incorrect
Option (1) Clock wise — Incorrect. A clockwise current would produce an inward field and add to the decrease of the outward flux, which Lenz's law does not allow.
Option (3) Current will not be induced — Incorrect. The flux through the coil changes, so an emf and a current are induced in the closed copper coil.
Option (4) Information is insufficient — Incorrect. The direction of the field and the sense of its change are both given, which is all Lenz's law needs.
NCERT (2026-27):
Lenz’s Law and Conservation of Energy – “In 1834, German physicist Heinrich Friedrich Lenz (1804-1865) deduced a rule, known as Lenz’s law which gives the polarity of the induced emf in a clear and concise fashion. The statement of the law is: The polarity of induced emf is such that it tends to produce a current which opposes the change in magnetic flux that produced it.”