JEE Main 2021PhysicsMechanical Properties of FluidsHardNumerical

JEE Main 2021 — Mechanical Properties of Fluids Question with Solution

JEE Main 2021 (17 Mar Shift 2)

Question

Suppose you have taken a dilute solution of oleic acid in such a way that its concentration becomes 0.01 cm3 of oleic acid per cm3 of the solution. Then you make a thin film of this solution (monomolecular thickness) of area 4 cm2 by considering 100 spherical drops of radius 340π13×10-3 cm. Then the thickness of oleic acid layer will be x×10-14 m. Where x is ________ .

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Show full solutionCorrect answer: 25
Correct answer
25

Step-by-step explanation

4tT=100×43πr3

=100×4π3×340π×10-9=10-8 cm3

tT=25×10-10 cm=25×10-12 m

t0=0.01tT=25×10-14 m⇒x=25.

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About this question

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