JEE Main · Physics · Thermal Properties of Matter
Thermal Expansion: JEE Main previous year questions
16 questions in the 108 JEE Main shifts Lumi analysed, in 7 of 8 years. Pattern: Asked most years. 3 came in 2024–26. Here is how it is asked and which ideas come back.
- Questions
- 16
- in 16 of 108 shifts
- Years asked
- 7/8
- last asked 2026
- Weighted estimate
- 0.1
- model; history: 0.2 a shift on average, typically 0.1–0.2
Key findings
- 01
Asked in 7 of 8 years with analysed shifts and in 16 of 108 shifts: 16 questions, #156 of 196 topics. The years that asked it were 1.5 apart on average.
- 02
60% of its questions since 2020 tested an idea no earlier year had asked; 1 repeated an idea from the year before.
- 03
The most repeated idea is Thermal Stress, asked 4 times in 4 shifts (2017, 2021, 2023), most often as “thermal force in clamped rod”.
- 04
JEE Main has asked 10 of the 54 ideas in this topic; 43 have never been asked, directly or inside another question.
- 05
Mostly asked as single correct (63%); 25% need a numerical answer, 50% are easy and 0% hard.
- 06
The skill tested most is calculation (69%), then application (13%).
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: 1 in 1 shift · 2020: 2 in 12 shifts · 2021: 6 in 24 shifts · 2022: 3 in 24 shifts · 2023: 1 in 12 shifts · 2024: 0 in 18 shifts · 2025: 1 in 8 shifts · 2026: 2 in 9 shifts.
- Up to 2023
- 0.3
- a shift, of 25
- Since 2024
- 0.1
- -0.2
- Usual gap
- 1.5 yrs
- between years asking it
- Shifts with it
- 16/108
- 15% of analysed shifts
How it is asked
Difficulty, format and skill
Across all 16 questions on Thermal Expansion since 2017.
Difficulty
QUESTIONS- Easy8 · 50%
- Medium8 · 50%
- Hard0 · 0%
Format
SHARE- Single correct · 10 Q63%
- Numerical value · 4 Q25%
- Diagram based · 1 Q6%
- Assertion–reason · 1 Q6%
Skill tested
SHARE- Calculation · 11 Q69%
- Application · 2 Q13%
- Multi-step · 2 Q13%
- Conceptual · 1 Q6%
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 10 of the 54 ideas in this topic. 43 have never been asked yet.
- Asked directly10 · 19%
- Touched inside another question1 · 2%
- Never asked43 · 80%
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.
10 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
10 different ideas were tested; 4 came more than once.
thermal force in clamped rod
Single correct · 4 shifts · 1 numericalexpansion over successive temperature intervals
Numerical value · 2 shifts · 1 numericalcoefficient of volume expansion of gas in a process
Single correct · 2 shiftsvolume expansion of heated cube
Single correct · 2 shiftschange in area from heat supplied to sheet
Single correct · 1 shiftrod length for constant difference
Numerical value · 1 shift · 1 numericaltemperature to fit ring on larger diameter
Single correct · 1 shiftbending direction of bimetallic strip
Diagram based · 1 shiftmercury volume for constant unfilled volume
Numerical value · 1 shift · 1 numericalpercentage change in density on heating
Single correct · 1 shift
| Idea | Years asked | Times | Shifts | Format | Numerical |
|---|---|---|---|---|---|
| Thermal Stressthermal force in clamped rod | 4 | 4 | Single correctCalculation | 1 | |
| Linear Expansionexpansion over successive temperature intervals | 2 | 2 | Numerical valueApplication | 1 | |
| Volume Expansion Coefficient of Ideal Gascoefficient of volume expansion of gas in a process | 2 | 2 | Single correctCalculation | – | |
| Volume Expansionvolume expansion of heated cube | 2 | 2 | Single correctCalculation | – | |
| Superficial Expansionchange in area from heat supplied to sheet | 1 | 1 | Single correctCalculation | – | |
| Constant Length Differencerod length for constant difference | 1 | 1 | Numerical valueCalculation | 1 | |
| Shrink Fitting and Interferencetemperature to fit ring on larger diameter | 1 | 1 | Single correctCalculation | – | |
| Bimetallic Stripsbending direction of bimetallic strip | 1 | 1 | Diagram basedApplication | – | |
| Apparent Expansion of Liquidsmercury volume for constant unfilled volume | 1 | 1 | Numerical valueCalculation | 1 | |
| Density Variation with Temperaturepercentage change in density on heating | 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
Thermal Expansion 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
- 4 Apr, Shift 2Q34The temperature of a metal strip having coefficient of linear expansion is increased from to resulting in increase of…
Idea: Linear Expansion
MediumSingle correct - 5 Apr, Shift 2Q34An ideal gas at pressure and temperature is expanding such that = constant. The coefficient of volume expansion of the gas…
Idea: Volume Expansion Coefficient of Ideal Gas
MediumSingle correct
JEE Main 20251 question in 1 shift
- 4 Apr, Shift 2Q31Consider a rectangular sheet of solid material of length cm and width cm. The coefficient of linear expansion is…
Idea: Superficial Expansion
New ideaMediumSingle correct
JEE Main 20231 question in 1 shift
- 8 Apr, Shift 2Q52A steel rod of length 1 m and cross sectional area m is heated from C to C without being allowed to…
Idea: Thermal Stress
EasyNumerical value
JEE Main 20223 questions in 3 shifts
- 25 Jul, Shift 1Q54A unit scale is to be prepared whose length does not change with temperature and remains cm, using a bimetallic strip made of brass…
Idea: Constant Length Difference
New ideaEasyNumerical value - 25 Jun, Shift 2Q34A solid metallic cube having total surface area is uniformly heated. If its temperature is increased by…
Idea: Volume Expansion
Asked the year beforeMediumSingle correct - 29 Jun, Shift 2Q32At what temperature a gold ring of diameter 6.230 cm be heated so that it can be fitted on a wooden bangle of diameter 6.241 cm ? Both the…
Idea: Shrink Fitting and Interference
New ideaEasySingle correct
JEE Main 20216 questions in 6 shifts
- 3 Aug, Shift 1Q27Two rods X and Y of identical dimensions are at temperature 40°C. If X is heated upto 200°C and Y is heated upto T°C, then also the new…
Idea: Linear Expansion
New ideaMediumNumerical value - 4 Aug, Shift 1Q16A steel wire of 1 mm cross-sectional area having Young’s modulus N/m is stretched between two fixed points at a…
Idea: Thermal Stress
EasySingle correct - 27 Aug, Shift 1Q7An ideal gas is expanding such that constant. The coefficient of volume expansion of the gas is :
Idea: Volume Expansion Coefficient of Ideal Gas
New ideaMediumSingle correct - 24 Feb, Shift 1Q6Each side of a box made of metal sheet in cubic shape is ‘a’ at room temperature ‘T’, the coefficient of linear expansion of the metal…
Idea: Volume Expansion
New ideaEasySingle correct - 25 Feb, Shift 1Q9Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R. Assertion A : When a rod lying…
Idea: Thermal Stress
EasyAssertion–reason - 16 Mar, Shift 2Q13A bimetallic strip consists of metals A and B. It is mounted rigidly as shown. The metal A has higher coefficient of expansion compared to…
Idea: Bimetallic Strips
New ideaEasyDiagram based · figure
JEE Main 20202 questions in 2 shifts
- 2 Sep, Shift 2Q6When the temperature of a metal wire is increased from 0°C to 10°C, its length increases by 0.02%. The percentage change in its mass…
Idea: Density Variation with Temperature
New ideaEasySingle correct - 3 Sep, Shift 1Q23A bakelite beaker has volume capacity of 500 cc at 30°C. When it is partially filled with V volume (at 30°C) of mercury, it is found…
Idea: Apparent Expansion of Liquids
New ideaMediumNumerical value
JEE Main 20171 question in 1 shift
- 2 Apr (offline)Q9An external pressure P is applied on a cube at 0°C so that it is equally compressed from all sides. K is the bulk modulus of the material…
Idea: Thermal Stress
MediumSingle correct
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.