JEE Main · Physics · Mechanical Properties of Fluids
Viscosity: JEE Main previous year questions
26 questions in the 108 JEE Main shifts Lumi analysed, in 6 of 8 years. Pattern: Asked most years. 8 came in 2024–26. Here is how it is asked and which ideas come back.
- Questions
- 26
- in 25 of 108 shifts
- Years asked
- 6/8
- last asked 2026
- Weighted estimate
- 0.2
- model; history: 0.2 a shift on average, typically 0.0–0.3
Key findings
- 01
Asked in 6 of 8 years with analysed shifts and in 25 of 108 shifts: 26 questions, #121 of 196 topics.
- 02
58% of its questions since 2020 tested an idea no earlier year had asked; 8 repeated an idea from the year before.
- 03
The most repeated idea is Terminal Velocity Calculation, asked 7 times in 7 shifts (2022, 2023, 2024), most often as “viscous force at terminal velocity”.
- 04
JEE Main has asked 11 of the 55 ideas in this topic; 43 have never been asked, directly or inside another question.
- 05
Mostly asked as single correct (65%); 23% need a numerical answer, 23% are easy and 4% hard.
- 06
The skill tested most is calculation (42%), then application (19%).
Questions a shift, year by year
Out of the 25 Physics questions in a shift. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift.
Raw count: 2017: 0 in 1 shift · 2020: 0 in 12 shifts · 2021: 2 in 24 shifts · 2022: 12 in 24 shifts · 2023: 4 in 12 shifts · 2024: 5 in 18 shifts · 2025: 1 in 8 shifts · 2026: 2 in 9 shifts.
- Up to 2023
- 0.1
- a shift, of 25
- Since 2024
- 0.2
- 0.0
- Usual gap
- 1.0 yrs
- between years asking it
- Shifts with it
- 25/108
- 23% of analysed shifts
How it is asked
Difficulty, format and skill
Across all 26 questions on Viscosity since 2017.
Difficulty
QUESTIONS- Easy6 · 23%
- Medium19 · 73%
- Hard1 · 4%
Format
SHARE- Single correct · 17 Q65%
- Numerical value · 6 Q23%
- Assertion–reason · 2 Q8%
- Match the list · 1 Q4%
Skill tested
SHARE- Calculation · 11 Q42%
- Application · 5 Q19%
- Multi-step · 4 Q15%
- Recall · 3 Q12%
- Conceptual · 2 Q8%
- Data or graph · 1 Q4%
Repeats
New idea, or one asked before?
Each column is a year. Blue questions tested an idea no earlier year had asked; navy ones went back to an idea from an earlier year. 2017 is the first year, so everything in it counts as new. Heights are question counts, and Lumi analysed 1 to 24 shifts a year, so compare the split inside a column rather than heights across years.
- Idea asked for the first time
- Idea asked in an earlier year
Coverage of the topic
JEE Main has asked 11 of the 55 ideas in this topic. 43 have never been asked yet.
- Asked directly11 · 20%
- Touched inside another question1 · 2%
- Never asked43 · 78%
Ideas come from Lumi’s JEE syllabus map. A never-asked idea is not a safe skip: across all of JEE Main, 22% of questions since 2024 tested an idea no earlier year had asked.
Drill down
Chapter, idea, question
Every idea JEE Main tested in this topic, with its eight years. Open one to read the questions.
9 ideas inside
Squares are the 8 years with analysed shifts, 2017 to 2026. A number is the questions that year when there is more than one; the shade is scaled to one shift, so a year with more analysed shifts (1 to 24 a year) does not look darker. Share is of the level above.
Ideas
Every idea inside this topic
11 different ideas were tested; 6 came more than once.
viscous force at terminal velocity
Single correct · 7 shifts · 2 numericalviscosity from terminal velocity
Numerical value · 4 shifts · 2 numericaldimension of physical quantity in new base units
Single correct · 4 shiftsterminal velocity ratio after drop splitting
Assertion–reason · 2 shiftsterminal velocity ratio for changed radius
Single correct · 2 shiftsterminal velocity of coalesced drop
Numerical value · 2 shifts · 1 numericalviscosity from terminal velocity
Single correct · 1 shiftgraph interpretation of falling ball in viscous liquid
Single correct · 1 shiftdepth from shear stress and velocity
Numerical value · 1 shift · 1 numericaldefinition recall
Single correct · 1 shiftviscous force at terminal velocity
Single correct · 1 shift
| Idea | Years asked | Times | Shifts | Format | Numerical |
|---|---|---|---|---|---|
| Terminal Velocity Calculationviscous force at terminal velocity | 7 | 7 | Single correctApplication | 2 | |
| Terminal Velocity of Rising Bubblesviscosity from terminal velocity | 4 | 4 | Numerical valueCalculation | 2 | |
| Units and Dimensions of Viscositydimension of physical quantity in new base units | 4 | 4 | Single correctRecall | – | |
| Terminal Velocity Radius Proportionalityterminal velocity ratio after drop splitting | 2 | 2 | Assertion–reasonMulti-step | – | |
| Radius Dependence of Terminal Velocityterminal velocity ratio for changed radius | 2 | 2 | Single correctApplication | – | |
| Terminal Velocity of Coalescing Dropsterminal velocity of coalesced drop | 2 | 2 | Numerical valueCalculation | 1 | |
| Falling Sphere Viscometryviscosity from terminal velocity | 1 | 1 | Single correctCalculation | – | |
| Velocity-Time Graph of Terminal Velocitygraph interpretation of falling ball in viscous liquid | 1 | 1 | Single correctData or graph | – | |
| Newton's Law of Viscositydepth from shear stress and velocity | 1 | 1 | Numerical valueCalculation | 1 | |
| Reynolds Numberdefinition recall | 1 | 1 | Single correctRecall | – | |
| Stokes' Lawviscous force at terminal velocity | 1 | 1 | Single correctCalculation | – |
Times and shifts count every analysed shift. Across JEE Main, 78% of questions since 2024 went back to an idea an earlier year had asked; the rest were new. All repeated ideas
Every question
Viscosity questions, year by year
The opening words of each question as it appeared in the official paper, with the idea it tested. Open one for its options and the official answer.
JEE Main 20262 questions in 2 shifts
- 2 Apr, Shift 2Q35If an air bubble of diameter 2 mm rises steadily through a liquid of density 2000 kg/m at a rate of 0.5 cm/s, then the coefficient of…
Idea: Terminal Velocity of Rising Bubbles
MediumSingle correct - 8 Apr, Shift 2Q34A spherical liquid drop of radius acquires the terminal velocity when falls through a gas of viscosity . Now the drop is…
Idea: Terminal Velocity Radius Proportionality
MediumSingle correct
JEE Main 20251 question in 1 shift
- 3 Apr, Shift 2Q32A solid steel ball of diameter 3.6 mm acquired terminal velocity m/s while falling under gravity through an oil of…
Idea: Falling Sphere Viscometry
New ideaEasySingle correct
JEE Main 20245 questions in 5 shifts
- 6 Apr, Shift 1Q35A small ball of mass m and density is dropped in a viscous liquid of density . After sometime, the ball falls with constant…
Idea: Terminal Velocity Calculation
Asked the year beforeMediumSingle correct - 8 Apr, Shift 2Q53Small water droplets of radius 0.01 mm are formed in the upper atmosphere and falling with a terminal velocity of 10 cm/s. Due to…
Idea: Terminal Velocity of Coalescing Drops
Asked the year beforeMediumNumerical value - 9 Apr, Shift 2Q40A spherical ball of radius m and density falls freely under gravity through a distance before…
Idea: Terminal Velocity Calculation
Asked the year beforeHardSingle correct - 31 Jan, Shift 1Q37A small steel ball is dropped into a long cylinder containing glycerine. Which one of the following is the correct representation of the…
Idea: Velocity-Time Graph of Terminal Velocity
New ideaEasySingle correct · figure - 31 Jan, Shift 2Q37A small spherical ball of radius , falling through a viscous medium of negligible density has terminal velocity 'v'. Another ball of…
Idea: Radius Dependence of Terminal Velocity
MediumSingle correct
JEE Main 20234 questions in 4 shifts
- 6 Apr, Shift 1Q33A small ball of mass M and density is dropped in a viscous liquid of density . After some time, the ball falls with a…
Idea: Terminal Velocity Calculation
Asked the year beforeEasySingle correct - 8 Apr, Shift 1Q52An air bubble of diameter rises steadily through a solution of density at the rate of…
Idea: Terminal Velocity of Rising Bubbles
Asked the year beforeMediumNumerical value - 11 Apr, Shift 2Q36Eight equal drops of water are falling through air with a steady speed of . If the drops coalesce, the new velocity is:-
Idea: Terminal Velocity of Coalescing Drops
New ideaMediumSingle correct - 13 Apr, Shift 2Q36Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R Assertion A : A spherical body of…
Idea: Terminal Velocity Radius Proportionality
New ideaMediumAssertion–reason
JEE Main 202212 questions in 11 shifts
- 25 Jul, Shift 1Q31If momentum [P], area [A] and time [T] are taken as fundamental quantities, then the dimensional formula for coefficient of viscosity is :
Idea: Units and Dimensions of Viscosity
Asked the year beforeMediumSingle correct - 28 Jul, Shift 1Q58The diameter of an air bubble which was initially 2 mm, rises steadily through a solution of density 1750 kg m at the rate of 0.35…
Idea: Terminal Velocity of Rising Bubbles
New ideaMediumNumerical value - 29 Jul, Shift 2Q54The 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…
Idea: Terminal Velocity Calculation
New ideaMediumNumerical value - 25 Jun, Shift 1Q36The terminal velocity () of the spherical rain drop depends on the radius (r) of the spherical rain drop as :
Idea: Radius Dependence of Terminal Velocity
New ideaEasySingle correct - 25 Jun, Shift 1Q53The velocity of upper layer of water in a river is 36 . Shearing stress between horizontal layers of water is…
Idea: Newton's Law of Viscosity
New ideaMediumNumerical value - 26 Jun, Shift 2Q36If is the density and is coefficient of viscosity of fluid which flows with a speed in the pipe of diameter d, the correct…
Idea: Reynolds Number
New ideaEasySingle correct - 27 Jun, Shift 1Q39The velocity of a small ball of mass ‘m’ and density , when dropped in a container filled with glycerine, becomes constant after some…
Idea: Terminal Velocity Calculation
New ideaMediumSingle correct - 27 Jun, Shift 2Q31The SI unit of a physical quantity is pascal-second. The dimensional formula of this quantity will be :
Idea: Units and Dimensions of Viscosity
Asked the year beforeEasySingle correct - 28 Jun, Shift 1Q31Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R. Assertion A : Product of Pressure…
Idea: Units and Dimensions of Viscosity
Asked the year beforeMediumAssertion–reason - 28 Jun, Shift 2Q37A 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…
Idea: Terminal Velocity Calculation
New ideaMediumSingle correct - 29 Jun, Shift 2Q52A small spherical ball of radius 0.1 mm and density falls freely under gravity through a distance before…
Idea: Terminal Velocity Calculation
New ideaMediumNumerical value - 30 Jun, Shift 1Q35An air bubble of negligible weight having radius r rises steadily through a solution of density σ at speed . The coefficient of…
Idea: Terminal Velocity of Rising Bubbles
New ideaMediumSingle correct
JEE Main 20212 questions in 2 shifts
- 27 Aug, Shift 1Q1In Millikan’s oil drop experiment, what is viscous force acting on an uncharged drop of radius m and density…
Idea: Stokes' Law
New ideaMediumSingle correct - 27 Aug, Shift 2Q2Match List - I with List - II. List - I List - II (a) (Rydberg constant) (i) (b) h(Planck's…
Idea: Units and Dimensions of Viscosity
New ideaMediumMatch the list
Questions from the official JEE Main Paper 1 shifts published by NTA (CBSE for 2017). Questions NTA dropped are left out. Topic and idea tags, counts and notes are Lumi’s.