JEE Main · Physics · Mechanical Properties of Fluids
Surface Tension: JEE Main previous year questions
36 questions in the 108 JEE Main shifts Lumi analysed, in 7 of 8 years. Pattern: Asked most years. 18 came in 2024–26. Here is how it is asked and which ideas come back.
- Questions
- 36
- in 33 of 108 shifts
- Years asked
- 7/8
- last asked 2026
- Weighted estimate
- 0.3
- model; history: 0.3 a shift on average, typically 0.1–0.4
Key findings
- 01
Asked in 7 of 8 years with analysed shifts and in 33 of 108 shifts: 36 questions, #94 of 196 topics.
- 02
53% 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 Splitting and Coalescence, asked 10 times in 10 shifts (2021, 2022, 2024, 2025, 2026), most often as “surface energy ratio on coalescence”.
- 04
JEE Main has asked 18 of the 54 ideas in this topic; 35 have never been asked, directly or inside another question.
- 05
Mostly asked as single correct (47%); 36% need a numerical answer, 44% are easy and 0% hard. It went up from 0.2 to 0.4 questions a shift since 2024.
- 06
The skill tested most is calculation (67%), then conceptual (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: 4 in 12 shifts · 2021: 5 in 24 shifts · 2022: 7 in 24 shifts · 2023: 2 in 12 shifts · 2024: 11 in 18 shifts · 2025: 3 in 8 shifts · 2026: 4 in 9 shifts.
- Up to 2023
- 0.2
- a shift, of 25
- Since 2024
- 0.4
- 0.3
- Usual gap
- 1.0 yrs
- between years asking it
- Shifts with it
- 33/108
- 31% of analysed shifts
Revise first
- Splitting and Coalescence · asked 2021, 2022, 2024, 2025, 2026
- Excess Pressure in Soap Bubbles · asked 2020, 2022, 2024, 2025
- Work Done in Expanding a Soap Bubble · asked 2026
How it is asked
Difficulty, format and skill
Across all 36 questions on Surface Tension since 2017.
Difficulty
QUESTIONS- Easy16 · 44%
- Medium20 · 56%
- Hard0 · 0%
Format
SHARE- Single correct · 17 Q47%
- Numerical value · 13 Q36%
- Two statements · 4 Q11%
- Assertion–reason · 2 Q6%
Skill tested
SHARE- Calculation · 24 Q67%
- Conceptual · 7 Q19%
- Multi-step · 3 Q8%
- Recall · 1 Q3%
- Application · 1 Q3%
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 18 of the 54 ideas in this topic. 35 have never been asked yet.
- Asked directly18 · 33%
- Touched inside another question1 · 2%
- Never asked35 · 65%
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.
17 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
18 different ideas were tested; 5 came more than once.
surface energy ratio on coalescence
Single correct · 10 shifts · 3 numericalvolume ratio from excess pressure of bubbles
Numerical value · 6 shifts · 3 numericalstatement i/ii on capillary rise
Numerical value · 3 shifts · 1 numericalstatement i/ii on contact angle and capillary rise
Assertion–reason · 2 shiftsradius of bubble from work done in blowing
Numerical value · 2 shifts · 2 numericalwork done expanding soap bubble
Numerical value · 1 shift · 1 numericalwork done expanding soap bubble
Single correct · 1 shiftcolumn length in tilted capillary
Single correct · 1 shiftstatement i/ii on fluid properties
Two statements · 1 shiftstatement i/ii on contact angle and capillarity
Two statements · 1 shiftexcess pressure inside submerged air bubble
Numerical value · 1 shift · 1 numericalsurface tension from excess pressure
Numerical value · 1 shift · 1 numericalassertion on dimensional correctness of period formula
Assertion–reason · 1 shiftlevel difference in u-tube with unequal bores
Single correct · 1 shiftradius of curvature of common surface of coalescing bubbles
Single correct · 1 shiftradius of bubble formed by isothermal coalescence
Single correct · 1 shiftradius of equivalent soap bubble for same excess pressure
Numerical value · 1 shift · 1 numericalradius of droplet floating half immersed
Single correct · 1 shift
| Idea | Years asked | Times | Shifts | Format | Numerical |
|---|---|---|---|---|---|
| Splitting and Coalescencesurface energy ratio on coalescence | 10 | 10 | Single correctCalculation | 3 | |
| Excess Pressure in Soap Bubblesvolume ratio from excess pressure of bubbles | 6 | 6 | Numerical valueCalculation | 3 | |
| Capillary Rise (Ascent Formula)statement i/ii on capillary rise | 3 | 3 | Numerical valueCalculation | 1 | |
| Angle of Contactstatement i/ii on contact angle and capillary rise | 2 | 2 | Assertion–reasonConceptual | – | |
| Surface Energy and Workradius of bubble from work done in blowing | 2 | 2 | Numerical valueCalculation | 2 | |
| Work Done in Expanding a Soap Bubblework done expanding soap bubble | 1 | 1 | Numerical valueCalculation | 1 | |
| Work Done in Expanding a Soap Bubblework done expanding soap bubble | 1 | 1 | Single correctCalculation | – | |
| Capillary Rise in a Tilted Tubecolumn length in tilted capillary | 1 | 1 | Single correctCalculation | – | |
| Effect of Temperature and Impuritiesstatement i/ii on fluid properties | 1 | 1 | Two statementsConceptual | – | |
| Young's Equation for Contact Anglestatement i/ii on contact angle and capillarity | 1 | 1 | Two statementsConceptual | – | |
| Excess Pressure in Submerged Air Bubblesexcess pressure inside submerged air bubble | 1 | 1 | Numerical valueCalculation | 1 | |
| Excess Pressure in Dropssurface tension from excess pressure | 1 | 1 | Numerical valueCalculation | 1 | |
| Oscillation Frequency of a Liquid Dropassertion on dimensional correctness of period formula | 1 | 1 | Assertion–reasonConceptual | – | |
| Capillary Difference in a U-Tubelevel difference in u-tube with unequal bores | 1 | 1 | Single correctCalculation | – | |
| Common Interface of Coalescing Bubblesradius of curvature of common surface of coalescing bubbles | 1 | 1 | Single correctConceptual | – | |
| Isothermal Coalescence of Bubblesradius of bubble formed by isothermal coalescence | 1 | 1 | Single correctMulti-step | – | |
| Pressure in Concentric Soap Bubblesradius of equivalent soap bubble for same excess pressure | 1 | 1 | Numerical valueCalculation | 1 | |
| Surface Tension Force on a Floating Sphereradius of droplet floating half immersed | 1 | 1 | Single correctMulti-step | – |
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
Surface Tension 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 20264 questions in 4 shifts
- 2 Apr, Shift 1Q45A liquid drop of diameter mm breaks into droplets. The change in surface energy is J. The value of…
Idea: Splitting and Coalescence
Asked the year beforeEasySingle correct - 2 Apr, Shift 2Q33The surface tension of a soap bubble is 0.03 N/m. The work done in increasing the diameter of bubble from 2 cm to 6 cm is…
Idea: Work Done in Expanding a Soap Bubble
New ideaEasySingle correct - 4 Apr, Shift 1Q47The surface tension of a soap solution is N/m. The work required to increase the radius of a soap bubble from cm to…
Idea: Work Done in Expanding a Soap Bubble
New ideaMediumNumerical value - 5 Apr, Shift 2Q33Eight mercury drops, each of radius , coalesce to form a bigger drop. The surface energy released in this process is __________. (S is…
Idea: Splitting and Coalescence
Asked the year beforeEasySingle correct
JEE Main 20253 questions in 3 shifts
- 2 Apr, Shift 2Q31Two water drops each of radius coalesce to form a bigger drop. If is the surface tension, the surface energy released in this…
Idea: Splitting and Coalescence
Asked the year beforeEasySingle correct - 3 Apr, Shift 2Q47The excess pressure inside a soap bubble A in air is half the excess pressure inside another soap bubble B in air. If the volume of the…
Idea: Excess Pressure in Soap Bubbles
Asked the year beforeEasyNumerical value - 7 Apr, Shift 2Q32A capillary tube of radius 0.1 mm is partly dipped in water (surface tension 70 dyn/cm and glass water contact angle )…
Idea: Capillary Rise in a Tilted Tube
New ideaMediumSingle correct
JEE Main 202411 questions in 11 shifts
- 4 Apr, Shift 1Q53A soap bubble is blown to a diameter of 7 cm. 36960 erg of work is done in blowing it further. If surface tension of soap solution is 40…
Idea: Surface Energy and Work
Asked the year beforeMediumNumerical value - 4 Apr, Shift 2Q38Given below are two statements : Statement I : The contact angle between a solid and a liquid is a property of the material of the solid…
Idea: Angle of Contact
MediumTwo statements - 5 Apr, Shift 1Q37Given below are two statements : Statement I : When a capillary tube is dipped into a liquid, the liquid neither rises nor falls in the…
Idea: Young's Equation for Contact Angle
New ideaMediumTwo statements - 6 Apr, Shift 1Q54A big drop is formed by coalescing 1000 small droplets of water. The ratio of surface energy of 1000 droplets to that of energy of big…
Idea: Splitting and Coalescence
EasyNumerical value - 6 Apr, Shift 2Q38Pressure inside a soap bubble is greater than the pressure outside by an amount : (given : = Radius of bubble, = Surface tension…
Idea: Excess Pressure in Soap Bubbles
EasySingle correct - 8 Apr, Shift 1Q53A liquid column of height 0.04 cm balances excess pressure of a soap bubble of certain radius. If density of liquid is…
Idea: Excess Pressure in Soap Bubbles
MediumNumerical value - 9 Apr, Shift 2Q39The excess pressure inside a soap bubble is thrice the excess pressure inside a second soap bubble. The ratio between the volume of the…
Idea: Excess Pressure in Soap Bubbles
EasySingle correct - 1 Feb, Shift 2Q37A big drop is formed by coalescing 1000 small droplets of water. The surface energy will become :
Idea: Splitting and Coalescence
EasySingle correct - 27 Jan, Shift 1Q37Given below are two statements : Statement (I) : Viscosity of gases is greater than that of liquids. Statement (II) : Surface tension of a…
Idea: Effect of Temperature and Impurities
New ideaMediumTwo statements - 29 Jan, Shift 1Q37Given below are two statements: Statement I : If a capillary tube is immersed first in cold water and then in hot water, the height of…
Idea: Capillary Rise (Ascent Formula)
EasyTwo statements - 30 Jan, Shift 2Q53A big drop is formed by coalescing 1000 small identical drops of water. If be the total surface energy of 1000 small drops of water…
Idea: Splitting and Coalescence
EasyNumerical value
JEE Main 20232 questions in 2 shifts
- 11 Apr, Shift 2Q52The surface tension of soap solution is . The amount of work done required to increase the radius of…
Idea: Surface Energy and Work
New ideaMediumNumerical value - 15 Apr, Shift 1Q52There is an air bubble of radius 1.0 mm in a liquid of surface tension 0.075 Nm and density 1000 kg m at a depth of 10 cm…
Idea: Excess Pressure in Submerged Air Bubbles
New ideaMediumNumerical value
JEE Main 20227 questions in 6 shifts
- 26 Jul, Shift 1Q45A water drop of radius 1 cm is broken into 729 equal droplets. If surface tension of water is 75 dyne/cm, then the gain in surface energy…
Idea: Splitting and Coalescence
Asked the year beforeMediumSingle correct - 27 Jul, Shift 2Q58A spherical soap bubble of radius 3 cm is formed inside another spherical soap bubble of radius 6 cm. If the internal pressure of the…
Idea: Excess Pressure in Soap Bubbles
MediumNumerical value - 29 Jul, Shift 1Q31Given below are two statements : One is labelled as Assertion (A) and other is labelled as Reason (R). Assertion (A) : Time period of…
Idea: Oscillation Frequency of a Liquid Drop
New ideaMediumAssertion–reason - 29 Jul, Shift 1Q37Given below are two statements : One is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : Clothes…
Idea: Angle of Contact
New ideaEasyAssertion–reason - 30 Jul, Shift 2Q27A water drop of radius 1 cm is broken into eight equal droplets. Surface tension of water is 0.075 N m . The gain in surface energy…
Idea: Splitting and Coalescence
Asked the year beforeMediumNumerical value - 28 Jun, Shift 1Q36A water drop of diameter 2 cm is broken into 64 equal droplets. The surface tension of water is 0.075 N/m. In this process the gain in…
Idea: Splitting and Coalescence
Asked the year beforeMediumSingle correct - 30 Jun, Shift 1Q54The excess pressure inside a liquid drop is 500 . If the radius of the drop is 2 mm, the surface tension of liquid is…
Idea: Excess Pressure in Drops
New ideaEasyNumerical value
JEE Main 20215 questions in 4 shifts
- 26 Aug, Shift 1Q6Two narrow bores of diameter 5.0 mm and 8.0 mm are joined together to form a U-shaped tube open at both ends. If this U-tube contains…
Idea: Capillary Difference in a U-Tube
New ideaEasySingle correct - 26 Aug, Shift 1Q23A soap bubble of radius 3 cm is formed inside the another soap bubble of radius 6 cm. The radius of an equivalent soap bubble which has…
Idea: Pressure in Concentric Soap Bubbles
New ideaMediumNumerical value - 26 Feb, Shift 1Q6A large number of water drops, each of radius r, combine to have a drop of radius R. If the surface tension is T and mechanical equivalent…
Idea: Splitting and Coalescence
New ideaMediumSingle correct - 25 Jul, Shift 2Q8Two spherical soap bubbles of radii and in vacuum combine under isothermal conditions. The resulting bubble has a radius equal…
Idea: Isothermal Coalescence of Bubbles
New ideaMediumSingle correct - 17 Mar, Shift 1Q9When two soap bubbles of radii a and b (b > a) coalesce, the radius of curvature of common surface is :
Idea: Common Interface of Coalescing Bubbles
New ideaMediumSingle correct
JEE Main 20204 questions in 3 shifts
- 9 Jan, Shift 2Q9A small spherical droplet of density is floating exactly half immersed in a liquid of density and surface tension . The…
Idea: Surface Tension Force on a Floating Sphere
New ideaMediumSingle correct - 2 Sep, Shift 2Q7A capillary tube made of glass of radius 0.15 mm is dipped vertically in a beaker filled with methylene iodide (surface tension = 0.05…
Idea: Capillary Rise (Ascent Formula)
New ideaMediumSingle correct - 3 Sep, Shift 1Q6Pressure inside two soap bubbles are 1.01 and 1.02 atmosphere, respectively. The ratio of their volumes is :
Idea: Excess Pressure in Soap Bubbles
New ideaEasySingle correct - 3 Sep, Shift 1Q25When a long glass capillary tube of radius 0.015 cm is dipped in a liquid, the liquid rises to a height of 15 cm within it. If the contact…
Idea: Capillary Rise (Ascent Formula)
New ideaEasyNumerical value
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.