JEE Main 2020PhysicsMechanical Properties of FluidsHardMCQ

JEE Main 2020 — Mechanical Properties of Fluids Question with Solution

JEE Main 2020 (05 Sep Shift 1)

Question

A hollow spherical shell at outer radius R floats just submerged under the water surface. The inner radius of the shell is r . If the specific gravity of the shell material is 278 with respect to water, the value of r is:

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Show full solutionCorrect option: A
Correct answer
A89R

Step-by-step explanation

In equilibrium mg=FB

43πR3-r3ρ0g=43πR3ρwg

1-rR3278ρw=ρw

1-r3R3=927

1-13=r3R3

23=r3R3

rR=231/3

1-r3R3=827

r3R3=1-827=1927

r=0.89

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About this question

This is a previous-year question from JEE Main 2020, 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.