JEE Main 2020PhysicsMotion In One DimensionMediumMCQ

JEE Main 2020 — Motion In One Dimension Question with Solution

JEE Main 2020 (04 Sep Shift 2)

Question

A particle of charge q and mass m is subjected to an electric field E=E01–ax2 in the x-direction, where a and E0 are constants. Initially the particle was at rest at x=0. Other than the initial position the kinetic energy of the particle becomes zero when the distance of the particle from the origin is :

Choose an option

Show full solutionCorrect option: C
Correct answer
C3a

Step-by-step explanation

Wex=ΔK       K1-K1=0

∫0xqEdx=0

 q ∫0xE01-Qx2dx=0

qE0∫0x1-ax2dx=0

x-ax33=0

1-ax23=0

ax23=1

x2=3a

x=3a 

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About this question

This is a previous-year question from JEE Main 2020, covering the Motion In One Dimension 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.