JEE Main 2023PhysicsMagnetic Effects of CurrentHardMCQ

JEE Main 2023 — Magnetic Effects of Current Question with Solution

JEE Main 2023 (30 Jan Shift 2)

Question

A current carrying rectangular loop PQRS is made of uniform wire. The length PR=QS=5 cm and PQ=RS=100 cm. If ammeter current reading changes from I to 2I, the ratio of magnetic forces per unit length on the wire PQ due to wire RS in the two cases respectively fPQI:fPQ2I is:

Choose an option

Show full solutionCorrect option: B
Correct answer
B1:4

Step-by-step explanation

Force acting per unit length between two parallel wires is given by, f=μ0I1I22πd.

Clearly, f∝I1I2

Therefore, fPQI:fPQ2I=I×I2I×2I=1:4

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About this question

This is a previous-year question from JEE Main 2023, covering the Magnetic Effects of Current chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.