JEE Main 2021PhysicsElectrostaticsMediumMCQ

JEE Main 2021Electrostatics Question with Solution

JEE Main 2021 (20 Jul Shift 1)

Question

A certain charge Q is divided into two parts q and (Q-q). How should the charges Q and q be divided so that q and (Q-q) placed at a certain distance apart experience maximum electrostatic repulsion?

Choose an option

Show full solutionCorrect option: B
Correct answer
BQ=2q

Step-by-step explanation

Fq=kq(Q-q)L2=kL2qQ-q2
dFdq=0 when force is maximum
dFdq=kL2[Q-2q]=0
Q-2q=0Q=2q

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About this question

This is a previous-year question from JEE Main 2021, covering the Electrostatics 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.