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Saturday, 31 October

JEE Main · Physics · Thermodynamics

First Law in Phase Transitions

JEE Main asked First Law in Phase Transitions 2 times in 2 of the 108 shifts Lumi analysed, in 2021 and 2023. It belongs to First Law of Thermodynamics, in Thermodynamics (Physics). The longest wait between two years asking it was 2 years.

Updated 2026-10-24

Times asked
2
in 2 shifts
Years
2 of 8
First asked
2021
last in 2023
Pattern
Occasional
across the analysed shifts

Questions on this idea a shift, by year

2017–2026. Asked in 2021 and 2023. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift of 25 Physics questions.

00.050.10’170’200.03’210’220.07’230’240’250’26

Raw count: 2017: 0 in 1 shift · 2020: 0 in 12 shifts · 2021: 1 in 24 shifts · 2022: 0 in 24 shifts · 2023: 1 in 12 shifts · 2024: 0 in 18 shifts · 2025: 0 in 8 shifts · 2026: 0 in 9 shifts.

Shift by shift

Each square is one analysed shift, in date order. Open a filled one for that paper.

  • 20260 of 9
  • 20250 of 8
  • 20240 of 18
  • 20231 of 12
  • 20220 of 24
  • 20211 of 24
  • 20200 of 12
  • 20170 of 1

Asked in that shift More than once Not asked

How JEE Main framed it

Numerical value is the usual form. Skill tested: calculation.

  • Internal energy change in boiling at constant pressure
  • Internal energy change on vaporisation

Difficulty

Easy 1Medium 1Hard 0

1 of the 2 questions had a numerical answer.

Every question

All 2 questions

From the official JEE Main shift papers, newest first. Open one for the full question, the options and the official answer.

  1. 11 Apr 2023, Shift 1 · Q441 kg of water at 100∘100^\circC is converted into steam at 100∘100^\circC by boiling at atmospheric pressure. The volume of water changes from…MediumSingle correct
  2. 4 Aug 2021, Shift 1 · Q251 g of water at 100°C is converted into steam at the same temperature and at 1 atmospheric pressure. The change in internal energy is…EasyNumerical value

Shifts: 4 Aug 2021, Shift 1, 11 Apr 2023, Shift 1.

Same topic

Other ideas in First Law of Thermodynamics

First Law of Thermodynamics has 21 ideas JEE Main has asked; 10 of them came up in more than one question. The 12 most asked are below.

Topic analysisChapter analysisStudy this chapterAll repeated ideas