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Modern Physics

JEE Main level, numerical answer, medium

2 of 5

Question 2 of 5

The half life of a radioactive sample is $20$ days. The percentage of initial nuclei remaining undecayed after $60$ days is:

Show answer and solution

Answer: 12.5

Number of half lives

n = 60/20 = 3

. Remaining fraction

= (1/2)^3 = 1/8 = 12.5\%

JEE Main question paper PDF

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JEE Main 2025 Apr 2 Shift 1 question paper

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JEE Main Physics practice question on Modern Physics, with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.

The half life of a radioactive sample is 202020 days. The percentage of initial nuclei remaining undecayed after 606060 days is:

JEE Main question paper PDF

More Physics practice

The half life of a radioactive sample is $20$ days. The percentage of initial nuclei remaining undecayed after $60$ days is: