NEET UG · Physics · Mechanical Properties of Fluids

Surface Tension: NEET previous year questions

6 questions in ten years of NEET, in 6 of 10 papers. Pattern: Every year. Here is how it is asked and which ideas come back.

Asked in 10 years: 6; about 0.6 per paper
Years asked: 6/10; last asked 2025
Chance of a question next paper: 50%; historical rate, how we compute it
Weighted estimate: 0.6; model; history: 0.6 a paper on average, typically 0–1

Key findings

01
Asked in 6 of 10 papers, 6 questions in all: #130 of 204 topics by ten-year total. It comes back every 1.2 years on average. Last asked in 2025.
02
83% of its questions since 2018 tested an idea never asked before; none repeated an idea from the year before.
03
The most repeated idea is Excess Pressure in Bubbles, asked 2 times (2019, 2022), usually as “effect of expanding soap bubble on pressure”.
04
NEET has asked 4 of the 89 ideas in this topic; 84 have never been asked, directly or indirectly.
05
Mostly asked as numerical (67%); 50% easy, 17% hard.

Questions per year

Up to 2023: 0.5; per paper
Since 2024: 0.6; 0.1
Usual gap: 1.2 yrs; between papers asking it
Swing: ±0.5; questions, year to year

How it is asked

Difficulty, format and skill

Across all 6 questions on Surface Tension since 2017.

Difficulty

QUESTIONS

321

Easy3 · 50%
Medium2 · 33%
Hard1 · 17%

Format

Numerical · 4 Q67%
Figure-based · 1 Q17%
One-line MCQ · 1 Q17%

Skill tested

Multi-step · 2 Q33%
Calculation · 2 Q33%
Concept · 1 Q17%
Application · 1 Q17%

Repeats

New idea, or one asked before?

Each column is a paper. Blue questions tested an idea NEET had not asked before; navy ones went back to an idea from an earlier paper. 2017 is the first paper, so everything in it counts as new.

’17’18’19’20’21’22’23’24’25’26

Idea asked for the first time
Idea asked in an earlier paper

Coverage of the topic

NEET has asked 4 of the 89 ideas in this topic. 84 have never been asked yet.

Asked directly4 · 4%
Touched inside another question1 · 1%
Never asked84 · 94%

Ideas come from Lumi’s syllabus map of NCERT. A never-asked idea is not a safe skip: most new questions come from exactly these.

Drill down

Idea, year, question

Every idea NEET tested in this topic, with its ten papers. Open one to read the questions.

ideaAskedShareYears’17’18’19’20’21’22’23’24’25’26

Repeated2 · 33%33%2/10
- 2022 · Q4
  If a soap bubble expands, the pressure inside the bubble :
  easyOne-line MCQ
- 2019 · Q7
  A soap bubble, having radius of 1 mm, is blown from a detergent solution having a surface tension of $2.5\times10^{-2}$ N/m. The pressure…
  mediumNumericalNew idea
1 · 17%17%1/10
1 · 17%17%1/10
1 · 17%17%1/10
1 · 17%17%1/10

Squares are the ten papers, 2017 to 2026; darker means more questions. Share is of the level above.

Ideas

Every idea inside this topic

5 different ideas were tested; 1 came more than once. Excess Pressure in Bubbles is the foundation for 13 other ideas in the syllabus.

Excess Pressure in Bubbles2×
effect of expanding soap bubble on pressure
Numerical · 6% next · foundation for 13
Shape of a Liquid Surface1×
derive differential equation of liquid surface
Figure-based · 6% next
Lifting Force for a Disc1×
numerical
Numerical · 6% next
Work Done Expanding a Soap Bubble1×
numerical
Numerical · 4% next · foundation for 1
Mass of Liquid in a Capillary Tube1×
numerical
Numerical · 4% next

Idea	Times	Format	Chance next	Foundation for
Excess Pressure in Bubbleseffect of expanding soap bubble on pressure	2	NumericalConcept	6%	13 ideas
Shape of a Liquid Surfacederive differential equation of liquid surface	1	Figure-basedMulti-step	6%	–
Lifting Force for a Discnumerical	1	NumericalCalculation	6%	–
Work Done Expanding a Soap Bubblenumerical	1	NumericalCalculation	4%	1 ideas
Mass of Liquid in a Capillary Tubenumerical	1	NumericalApplication	4%	–

Chance next is the historical rate at which an idea with this record came back in the following paper. It is low for every idea, which is why learning the topic beats memorising past questions. 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.

NEET 20251 question

Q1
Consider a water tank shown in the figure. It has one wall at $x = L$ and can be taken to be very wide in the $z$ direction. When filled…
Idea: Shape of a Liquid Surface
New ideaHardFigure-based · figure

NEET 20241 question

Q24
A thin flat circular disc of radius 4.5 cm is placed gently over the surface of water. If surface tension of water is 0.07 N m $^{-1}$ ,…
Idea: Lifting Force for a Disc
New ideaEasyNumerical

NEET 20231 question

Q27
The amount of energy required to form a soap bubble of radius 2 cm from a soap solution is nearly : (surface tension of soap solution =…
Idea: Work Done Expanding a Soap Bubble
New ideaMediumNumerical

NEET 20221 question

Q4
If a soap bubble expands, the pressure inside the bubble :
Idea: Excess Pressure in Bubbles
EasyOne-line MCQ

NEET 20201 question

Q178
A capillary tube of radius r is immersed in water and water rises in it to a height h. The mass of the water in the capillary is 5 g.…
Idea: Mass of Liquid in a Capillary Tube
New ideaEasyNumerical

NEET 20191 question

Q7
A soap bubble, having radius of 1 mm, is blown from a detergent solution having a surface tension of $2.5\times10^{-2}$ N/m. The pressure…
Idea: Excess Pressure in Bubbles
New ideaMediumNumerical

Questions from the official NEET UG papers published by NTA (CBSE before 2019). Topic and idea tags, counts and notes are Lumi’s.