JEE Main 2014PhysicsMechanical Properties of FluidsMediumMCQ

JEE Main 2014 — Mechanical Properties of Fluids Question with Solution

JEE Main 2014 (06 Apr)

Question

On heating water, bubbles being formed at the bottom of the vessel detatch and rise. Take the bubbles to be spheres of radius R and making a circular contact of radius r with the bottom of the vessel. If r << R, and the surface tension of water is T, value of r just before bubbles detatch is :
(density of water is ρ w )

Choose an option

Show full solutionCorrect option: A
Correct answer
A R 2 2ρ w  g 3 T ​

Step-by-step explanation

When the bubble gets detached,

Buoyant force = force due to surface tension


∫ T × dl sin θ = 4 3 π R 3 ρ w g

⇒ T × 2 π r × r R = 4 3 π R 3 ρ w g
⇒ r 2 = 2 R 4 ρ w g 3T

Practice this on the real CBT interface

Solve this JEE Main question (and the rest of the Mechanical Properties of Fluids chapter) on PrepSharp's TCS iON-style CBT player — with timer, bookmarks and session analytics.

Solve interactively →

About this question

This is a previous-year question from JEE Main 2014, 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.