NEET 2026
- Exam
- NEET
- Year
- 2026
- Subject
- Physics
- Chapter
- Chapter
NEET 2026 · Physics · Chapter
A long, straight horizontal wire carries a steady current I from...
A long, straight horizontal wire carries a steady current from left to right as shown in the figure. Two circular conducting loops, P and Q, are placed in the same plane as the wire. Loop P is located above the wire and is moving vertically upwards with velocity . Loop Q is located below the wire and is also moving vertically upwards with velocity . According to Lenz's law, what will be the direction of the induced current in loops P and Q respectively?
Options
- AAnticlockwise in both P and Q
- BAnticlockwise in P and Clockwise in Q
- CClockwise in P and Anticlockwise in Q
- DClockwise in both P and Q
Correct answer
A. Anticlockwise in both P and Q
Step-by-step solution
According to the right-hand grip rule, the magnetic field produced by the straight current-carrying wire is directed out of the plane of the paper above the wire and into the plane of the paper below the wire.
For loop P:
It is located above the wire, so the magnetic field passing through it is directed outwards. As loop P moves vertically upwards (away from the wire), the strength of the magnetic field decreases, causing the outward magnetic flux to decrease. According to Lenz's law, the induced current will oppose this decrease by producing its own magnetic field directed outwards. By the right-hand rule, an outward magnetic field corresponds to an anticlockwise induced current.
For loop Q:
It is located below the wire, so the magnetic field passing through it is directed inwards. As loop Q moves vertically upwards (towards the wire), the strength of the magnetic field increases, causing the inward magnetic flux to increase. According to Lenz's law, the induced current will oppose this increase by producing its own magnetic field directed outwards (opposite to the inward field). By the right-hand rule, an outward magnetic field again corresponds to an anticlockwise induced current.
Therefore, the induced current is anticlockwise in both loops P and Q.
Answer: Anticlockwise in both P and Q
For loop P:
It is located above the wire, so the magnetic field passing through it is directed outwards. As loop P moves vertically upwards (away from the wire), the strength of the magnetic field decreases, causing the outward magnetic flux to decrease. According to Lenz's law, the induced current will oppose this decrease by producing its own magnetic field directed outwards. By the right-hand rule, an outward magnetic field corresponds to an anticlockwise induced current.
For loop Q:
It is located below the wire, so the magnetic field passing through it is directed inwards. As loop Q moves vertically upwards (towards the wire), the strength of the magnetic field increases, causing the inward magnetic flux to increase. According to Lenz's law, the induced current will oppose this increase by producing its own magnetic field directed outwards (opposite to the inward field). By the right-hand rule, an outward magnetic field again corresponds to an anticlockwise induced current.
Therefore, the induced current is anticlockwise in both loops P and Q.
Answer: Anticlockwise in both P and Q