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Saturday, 31 October

JEE Main · Physics · Nuclei

Successive Decay Chains

JEE Main asked Successive Decay Chains 3 times in 3 of the 108 shifts Lumi analysed, in 2021 and 2025. It belongs to Radioactive Decay, in Nuclei (Physics). The longest wait between two years asking it was 4 years. In 2021 it came in more than one shift of the same year.

Updated 2026-10-24

Times asked
3
in 3 shifts
Years
2 of 8
First asked
2021
last in 2025
Pattern
Occasional
across the analysed shifts

Questions on this idea a shift, by year

2017–2026. Asked in 2021 and 2025. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift of 25 Physics questions.

00.10.20’170’200.07’210’220’230’240.13’250’26

Raw count: 2017: 0 in 1 shift · 2020: 0 in 12 shifts · 2021: 2 in 24 shifts · 2022: 0 in 24 shifts · 2023: 0 in 12 shifts · 2024: 0 in 18 shifts · 2025: 1 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
  • 20251 of 8
  • 20240 of 18
  • 20230 of 12
  • 20220 of 24
  • 20212 of 24
  • 20200 of 12
  • 20170 of 1

Asked in that shift More than once Not asked

How JEE Main framed it

Diagram based is the usual form. Skill tested: data or graph.

  • Graph of successive radioactive decay masses
  • Graph of daughter nucleus population in decay chain

Difficulty

Easy 0Medium 2Hard 1

Every question was multiple choice.

Every question

All 3 questions

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

  1. 4 Apr 2025, Shift 2 · Q42A radioactive material P first decays into Q and then Q decays to non-radioactive material R. Which of the following figure represents…MediumDiagram basedHas a figure
  2. 31 Aug 2021, Shift 1 · Q3A sample of a radioactive nucleus A disintegrates to another radioactive nucleus B, which in turn disintegrates to some other stable…MediumDiagram basedHas a figure
  3. 26 Aug 2021, Shift 2 · Q6At time t=0t=0, a material is composed of two radioactive atoms A and B, where NA(0)=2NB(0)\mathrm{N_A(0)=2N_B(0)}. The decay constant of both kind…HardDiagram basedHas a figure

Shifts: 26 Aug 2021, Shift 2, 31 Aug 2021, Shift 1, 4 Apr 2025, Shift 2.

Same topic

Other ideas in Radioactive Decay

Radioactive Decay has 12 ideas JEE Main has asked; 9 of them came up in more than one question.

Topic analysisChapter analysisStudy this chapterAll repeated ideas