JEE Main 2022 · PhysicsMultiple choiceSingle correctMediumApplication

JEE Main 30 June 2022, Shift 1, Physics Q35

Question 35 of 90 in this shift, Physics question 5 of 30, Section A.

An air bubble of negligible weight having radius r rises steadily through a solution of density σ at speed

v

. The coefficient of viscosity of the solution is given by :

(1) $\eta = \frac{4r\sigma g}{9v}$
(2) $\eta = \frac{2r^2\sigma g}{9v}$ Official answer
(3) $\eta = \frac{2\pi r^2\sigma g}{9v}$
(4) $\eta = \frac{2r^2\sigma g}{3\pi v}$

Official answer

Option 2

NTA final key.

Chapter: Mechanical Properties of Fluids
Topic: Viscosity
Idea tested: Terminal Velocity of Rising Bubbles

Same idea in other shifts

Asked 4× in all

2 Apr 2026, Shift 2 · Q35If an air bubble of diameter 2 mm rises steadily through a liquid of density 2000 kg/m $^3$ at a rate of 0.5 cm/s, then the coefficient of…MediumSingle correct
8 Apr 2023, Shift 1 · Q52An air bubble of diameter $6\ \mathrm{mm}$ rises steadily through a solution of density $1750\ \mathrm{kg/m^3}$ at the rate of…MediumNumerical value
28 Jul 2022, Shift 1 · Q58The diameter of an air bubble which was initially 2 mm, rises steadily through a solution of density 1750 kg m $^{-3}$ at the rate of 0.35…MediumNumerical value

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.