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Saturday, 31 October

JEE Main · Physics · Nuclei

Activity from Sample Mass

JEE Main asked Activity from Sample Mass once in the 108 shifts Lumi analysed, on 25 Jul 2021, Shift 1. It belongs to Radioactive Decay, in Nuclei (Physics).

Updated 2026-10-24

Times asked
1
in 1 shift
Years
1 of 8
First asked
2021
the only year
Pattern
Gone quiet
asked once so far

Questions on this idea a shift, by year

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

00.050.10’170’200.03’210’220’230’240’250’26

Raw count: 2017: 0 in 1 shift · 2020: 0 in 12 shifts · 2021: 1 in 24 shifts · 2022: 0 in 24 shifts · 2023: 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
  • 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

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

  • Activity from mass and half-life

Difficulty

Easy 0Medium 1Hard 0

The question was multiple choice.

Every question

The question

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

  1. 25 Jul 2021, Shift 1 · Q1The half-life of 198Au^{198}\mathrm{Au} is 3 days. If atomic weight of 198Au^{198}\mathrm{Au} is 198 g/mol then the activity of 2 mg of…MediumSingle correct

Shift: 25 Jul 2021, Shift 1.

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