JEE Main 2017PhysicsElectrostaticsMediumMCQ

JEE Main 2017 — Electrostatics Question with Solution

JEE Main 2017 (02 Apr)

Question

An electric dipole has fixed dipole moment p→, which makes angle θ with respect to x-axis. When subjected to an electric field E→1=Ei^, it experiences a torque T→1=τk^. When subjected to another electric field E→2= 3 E1j^ it experiences a torque T→2=-T→1 . The angle θ is:

Choose an option

Show full solutionCorrect option: D
Correct answer
D60o

Step-by-step explanation

P→=Pcos⁡θi^+Psin⁡θj^

T→=Pcos⁡θi^+Psin⁡θj^×Ei^

=-PEsin⁡θk^

T→2=Pcos⁡θi^+Psin⁡θj^×3Ej^

= 3PEcos⁡θk^

T→2= -T→1

∴    sin⁡θ= 3cos⁡θ

∴    tan⁡θ= 3

∴   θ=60o

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About this question

This is a previous-year question from JEE Main 2017, 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.