Learn

Saturday, 31 October

JEE Main · Physics · Nuclei

Statistical Decay Law

JEE Main asked Statistical Decay Law 5 times in 5 of the 108 shifts Lumi analysed, in 2017, 2020, 2021 and 2022. It belongs to Radioactive Decay, in Nuclei (Physics). The longest wait between two years asking it was 3 years, across 2018 and 2019, which Lumi has no shifts for. In 2022 it came in more than one shift of the same year.

Updated 2026-10-24

Times asked
5
in 5 shifts
Years
4 of 8
First asked
2017
last in 2022
Pattern
Comes in cycles
across the analysed shifts

Questions on this idea a shift, by year

2017–2026. Asked in 2017, 2020, 2021 and 2022. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift of 25 Physics questions.

00.510.83’170.08’200.03’210.07’220’230’240’250’26

Raw count: 2017: 1 in 1 shift · 2020: 1 in 12 shifts · 2021: 1 in 24 shifts · 2022: 2 in 24 shifts · 2023: 0 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
  • 20230 of 12
  • 20222 of 24
  • 20211 of 24
  • 20201 of 12
  • 20171 of 1

Asked in that shift More than once Not asked

How JEE Main framed it

Single correct is the usual form. Skill tested: calculation.

  • Time interval between fractional decays
  • Time from daughter-to-parent ratio

Difficulty

Easy 1Medium 4Hard 0

1 of the 5 questions had a numerical answer.

Every question

All 5 questions

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

  1. 28 Jun 2022, Shift 2 · Q48Following statements related to radioactivity are given below : (A) Radioactivity is a random and spontaneous process and is dependent on…MediumOther
  2. 29 Jul 2022, Shift 2 · Q59Two radioactive materials A and B have decay constants 25λ25\lambda and 16λ16\lambda respectively. If initially they have the same number of…MediumNumerical value
  3. 25 Jul 2021, Shift 1 · Q5Some nuclei of a radioactive material are undergoing radioactive decay. The time gap between the instances when a quarter of the nuclei…MediumSingle correct
  4. 3 Sep 2020, Shift 1 · Q19In a radioactive material, fraction of active material remaining after time t is 9/16. The fraction that was remaining after t/2 is :EasySingle correct
  5. 2 Apr 2017 (offline) · Q26A radioactive nucleus A with a half life T, decays into a nucleus B. At t=0t=0, there is no nucleus B. At sometime t, the ratio of the…MediumSingle correct

Shifts: 2 Apr 2017 (offline), 3 Sep 2020, Shift 1, 25 Jul 2021, Shift 1, 28 Jun 2022, Shift 2, 29 Jul 2022, 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