JEE Main 2023PhysicsMagnetic Effects of CurrentHardMCQ

JEE Main 2023Magnetic Effects of Current Question with Solution

JEE Main 2023 (24 Jan Shift 1)

Question

Two long straight wires P and Q carrying equal current 10 A each were kept parallel to each other at 5 cm distance. Magnitude of magnetic force experienced by 10 cm length of wire P is F1. If distance between wires is halved and currents on them are doubled, force F2 on 10 cm length of wire P will be:

Choose an option

Show full solutionCorrect option: A
Correct answer
A8F1

Step-by-step explanation

As we know, force per unit length between two parallel straight wires is given by,  F=μ0i1i22πd.

Therefore, required ratio

F1 F2=μ0(10)22π(5×10-2)μ0(20)22π52×10-2=18

F2=8F1

Practice this on the real CBT interface

Solve this JEE Main question (and the rest of the Magnetic Effects of Current chapter) on PrepSharp's TCS iON-style CBT player — with timer, bookmarks and session analytics.

Solve interactively →

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.