JEE Main 2024PhysicsElectrostaticsHardNumerical

JEE Main 2024 — Electrostatics Question with Solution

JEE Main 2024 (01 Feb Shift 1)

Question

Two identical charged spheres are suspended by strings of equal lengths. The strings make an angle θ with each other. When suspended in water the angle remains the same. If density of the material of the sphere is 1.5 g/cc, the dielectric constant of water will be ______.

(Take density of water =1 g/cc)

Enter your answer

Show full solutionCorrect answer: 3
Correct answer
3

Step-by-step explanation

In air:

 tanθ2=Fmg=q24πε0r2mg

In water:

 tanθ2=F'mg'=q24πε0εrr2mgeff

Equate both equations, we get

ε0 g=ε0εrg1-11.5

⇒εr=3

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About this question

This is a previous-year question from JEE Main 2024, 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.