JEE Main 2021PhysicsMechanical Properties of FluidsEasyMCQ

JEE Main 2021 — Mechanical Properties of Fluids Question with Solution

JEE Main 2021 (27 Aug Shift 1)

Question

In Millikan's oil drop experiment, what is viscous force acting on an uncharged drop of radius 2.0×10-5 m and density 1.2×103 kg m-3? Take viscosity of liquid =1.8×10-5 N s m-2. (Neglect buoyancy due to air).

Choose an option

Show full solutionCorrect option: B
Correct answer
B3.9×10-10 N

Step-by-step explanation

Use the concept the viscous force is the same as the weight of the body, 

⇒F=mg=ρ×43πr3×g=3.9×10-10 N. 

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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.