JEE Main 2018PhysicsMechanical Properties of FluidsHardMCQ

JEE Main 2018 — Mechanical Properties of Fluids Question with Solution

JEE Main 2018 (15 Apr)

Question

A thin uniform tube is bent into a circle of radius r in the vertical plane. Equal volumes of two immiscible liquids, Whose densities are ρ1 and ρ2 (ρ1>ρ2 ), fill half the circle. The angle θ between the radius vector passing through the common interface and the vertical is:

Choose an option

Show full solutionCorrect option: B
Correct answer
B θ=tan-1⁡ρ1-ρ2ρ1+ρ2

Step-by-step explanation


Pressure at the point A is the same on both sides of the tube, 
ρ 1 gr(cosθ−sinθ)= ρ 2 gr(sinθ+cosθ)
⇒ρ1ρ2=sinθ+cosθcosθ-sinθ=tanθ+11-tanθ
⇒ρ1-ρ1tanθ=ρ2+ρ2tanθ
⇒ρ1+ρ2tanθ=ρ1-ρ2

θ=tan-1⁡ρ1-ρ2ρ1+ρ2

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About this question

This is a previous-year question from JEE Main 2018, 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.