A square loop is placed near a long straight current carrying wire as shown in figure. If the loop is moved away from the wire
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Wire will exert net attractive force on the loop
The wire carries current upward, so on its right side the field points into the page and weakens with distance. Moving the loop away decreases the inward flux, so by Lenz's law the induced current makes an inward field: a clockwise current.
The near side of the loop then carries current upward, parallel to the wire's current, and is attracted; the far side carries current downward and is repelled, but the field there is weaker. So there is a net attraction, which opposes the motion of the loop.
Option (1) Induced current in loop will be anti-clockwise — Incorrect. A decreasing inward flux is opposed by an inward field, so the current is clockwise.
Option (3) Wire will exert net repulsive force on the loop — Incorrect. A repulsion would help the loop move away; Lenz's law requires the force to oppose the motion.
Option (4) No current is induced in the loop — Incorrect. The flux through the loop changes, so a current is induced.
NCERT (2026-27):
Lenz’s Law and Conservation of Energy – “… 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.”
Lenz’s Law and Conservation of Energy – “… Similarly, if the North-pole of the magnet is being withdrawn from the coil, the magnetic flux through the coil will decrease. … This would result in an attractive force which opposes the motion of the magnet and the corresponding decrease in flux.”