JEE Main 2021PhysicsRotational MotionMediumMCQ

JEE Main 2021 — Rotational Motion Question with Solution

JEE Main 2021 (18 Mar Shift 2)

Question

A solid cylinder of mass m is wrapped with an inextensible light string and, is placed on a rough inclined plane as shown in the figure. The frictional force acting between the cylinder and the inclined plane is:

[The coefficient of static friction, μs, is 0.4 ]

Choose an option

Show full solutionCorrect option: C
Correct answer
Cmg5

Step-by-step explanation

Let's take solid cylinder is in equilibrium

T+f=mgsin60

TR-fR=0

Solving we get

T=freq=mgsinθ2

But limiting friction < required friction

μmgcos60°<mgsin60°2

∴ Hence cylinder will not remain in equilibrium

Hence f= kinetic

=μkN

=μkmgcos60°

=mg5

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About this question

This is a previous-year question from JEE Main 2021, covering the Rotational 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.