JEE Main 2019PhysicsLaws of MotionMediumMCQ

JEE Main 2019 — Laws of Motion Question with Solution

JEE Main 2019 (12 Jan Shift 2)

Question

A vertical closed cylinder is separated into two parts by a frictionless piston of mass m and of negligible thickness. The piston is free to move along the length of the cylinder. The length of the cylinder above piston is l1, and that below the piston is l2, such that l1>l2. Each part of the cylinder contains n moles of an ideal gas at equal temperature T. If the piston is stationary, its mass m will be given by:

(R is universal gas constant and g is the acceleration due to gravity)

Choose an option

Show full solutionCorrect option: B
Correct answer
BnRTgl1-l2l1l2

Step-by-step explanation

P1+mgA=P2

⇒nRTl1A+mgA=nRTl2A

⇒m=nRTg1l2-1l1

=nRTgl1-l2l1l2

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About this question

This is a previous-year question from JEE Main 2019, covering the Laws of Motion 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.