JEE Main 2021PhysicsWork Power EnergyHardMCQ

JEE Main 2021 — Work Power Energy Question with Solution

JEE Main 2021 (27 Jul Shift 2)

Question

Given below is the plot of a potential energy function U(x) for a system, in which a particle is in one dimensional motion, while a conservative force F(x) acts on it. Suppose that Emech =8 J, the incorrect statement for this system is :

Choose an option

Show full solutionCorrect option: B
Correct answer
Bat x<x1, K.E. is smallest and the particle is moving at the slowest speed.

Step-by-step explanation

(A) at x>x4,  U= constant =6 J

K=Emech. -U=2 J= constant

(B) at x<x1,  U= constant =8 J

K=Emech. -U=8-8=0 J

Particle is at rest.

(C) At x=x2,U=0⇒Emech. =K=8 J
KE is greatest, and particle is moving at fastest speed.

(D) At x=x3,  U=4 J

U+K=8 J

K=4 J

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About this question

This is a previous-year question from JEE Main 2021, covering the Work Power Energy 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.