JEE Main 2022PhysicsMechanical Properties of FluidsHardNumerical

JEE Main 2022 — Mechanical Properties of Fluids Question with Solution

JEE Main 2022 (29 Jul Shift 2)

Question

The velocity of a small ball of mass 0.3 g and density 8 g cc-1 when dropped in a container filled with glycerine becomes constant after some time. If the density of glycerine is 1.3 g cc-1, then the value of viscous force acting on the ball will be x×10-4 N, the value of x is _____ .

[use g=10 m s-2]

Enter your answer

Show full solutionCorrect answer: 25
Correct answer
25

Step-by-step explanation

Let FV be the viscous force and FB be the buoyant force acting on the ball.

​​​​​​​

Then, when body moves with constant velocity,

FV+FB=Mg   

Or, FV=Mg-FB

FV=ρBVg-ρLVg =ρB-ρLVg, where, V is the volume of small ball.

=8-1.3×103×0.3×10-38×103×10

=6.7×0.38×10-2

=67×38×10-4=25.125×10-4=25×10-4 N

Thus, the value of x=25.

Practice this on the real CBT interface

Solve this JEE Main question (and the rest of the Mechanical Properties of Fluids chapter) on PrepSharp's TCS iON-style CBT player — with timer, bookmarks and session analytics.

Solve interactively →

About this question

This is a previous-year question from JEE Main 2022, covering the Mechanical Properties of Fluids 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.