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Friday, 9 October

JEE Main Physics · Nuclei

Half-Life Calculations

Half-Life Calculations (Nuclei) was asked 5 times in 4 JEE Main shifts, 2021–2023, out of the 42 shifts Lumi analysed. 1 of the 5 had a numerical answer.

Times asked
5
in 4 shifts
Years
2021–2023
Usual format
Single correct
Calculation
Pattern
Comes in cycles
repeats across shifts

How it is asked

  • Time interval between fractional decays
  • Time for fractional decay of activity

Difficulty

Easy 4Medium 1Hard 0

Where it sits

Chapter: Nuclei. Topic: Radioactive Decay, 15 questions over 9 ideas.

Other repeat ideas in this topic

Every time it came

All 5 questions

Newest first, each with its options and official answer.

  1. 8 Apr 2023, Shift 2 · Q44A radio active material is reduced to 1/8 of its original amount in 3 days. If 8×10−38\times10^{-3} kg of the material is left after 5 days…MediumSingle correct
  2. 29 Jun 2022, Shift 1 · Q33The activity of a radioactive material is 2.56×10−32.56 \times 10^{-3} Ci. If the half life of the material is 5 days, after how many days the…EasySingle correct
  3. 3 Aug 2021, Shift 2 · Q18A radioactive isotope has a half life of T years. After how much time is its activity reduced to 6.25% of its original activity ?EasySingle correct
  4. 3 Aug 2021, Shift 2 · Q25A sample undergoing beta decay, reduced to 116th\frac{1}{16}^{\mathrm{th}} of its initial mass in 48 years. Its half life period is…EasyNumerical value
  5. 16 Mar 2021, Shift 2 · Q10Calculate the time interval between 33% decay and 67% decay if half-life of a substance is 20 minutes.EasySingle correct