JEE Main 2023 · PhysicsMultiple choiceSingle correctEasyApplication

JEE Main 6 April 2023, Shift 1, Physics Q33

Question 33 of 90 in this shift, Physics question 3 of 30, Section A.

A small ball of mass M and density

\rho

is dropped in a viscous liquid of density

\rho_0

. After some time, the ball falls with a constant velocity. What is the viscous force on the ball ?

(1) $F=Mg\left(1-\frac{\rho_0}{\rho}\right)$ Official answer
(2) $F=Mg\left(1+\frac{\rho_0}{\rho}\right)$
(3) $F=Mg\left(1+\frac{\rho}{\rho_0}\right)$
(4) $F=Mg(1\pm\rho\rho_0)$

Official answer

Option 1

NTA final key.

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

Same idea in other shifts

Asked 7× in all

6 Apr 2024, Shift 1 · Q35A small ball of mass m and density $\rho$ is dropped in a viscous liquid of density $\rho_0$ . After sometime, the ball falls with constant…MediumSingle correct
9 Apr 2024, Shift 2 · Q40A spherical ball of radius $1\times10^{-4}$ m and density $10^5\ \mathrm{kg/m^3}$ falls freely under gravity through a distance $h$ before…HardSingle correct
29 Jul 2022, Shift 2 · Q54The velocity of a small ball of mass 0.3 g and density 8 g/cc when dropped in a container filled with glycerine becomes constant after…MediumNumerical value
27 Jun 2022, Shift 1 · Q39The velocity of a small ball of mass ‘m’ and density $d_1$ , when dropped in a container filled with glycerine, becomes constant after some…MediumSingle correct
28 Jun 2022, Shift 2 · Q37A water drop of radius 1 µm falls in a situation where the effect of buoyant force is negligible. Co-efficient of viscosity of air is…MediumSingle correct
29 Jun 2022, Shift 2 · Q52A small spherical ball of radius 0.1 mm and density $10^4$ $\mathrm{kg\,m^{-3}}$ falls freely under gravity through a distance $h$ before…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.