JEE Main 2019PhysicsMechanical Properties of FluidsMediumMCQ

JEE Main 2019 — Mechanical Properties of Fluids Question with Solution

JEE Main 2019 (12 Apr Shift 2)

Question

A solid sphere, of radius R acquires a terminal velocity v1 when falling (due to gravity) through a viscous fluid having a coefficient of viscosity η. The sphere is broken into 27 identical solid spheres. If each of these spheres acquires a terminal velocity, v2, when falling through the same fluid, the ratio v1v2 equals:

Choose an option

Show full solutionCorrect option: D
Correct answer
D9

Step-by-step explanation

If R is the radius of initial drop and r is the radius of new drop, then
43πR3=27×43πr3⇒r=R3
Terminal velocity,

         vT∝r2
⇒ v1v2=R2R32=9

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About this question

This is a previous-year question from JEE Main 2019, 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.