A Geigger Muller counter is used to study the radioactive process. In the absence of radioactive substance $A$, it counts 3 disintegration per second (dps). At the start in the presence of $\mathrm{A}$, it records 23 dps; and after 10 min 13 dps,
(i) What does it count after $20 \mathrm{~min}$
(ii) What is the halflife of A?

Question

Aicharya · Accepted Answer

In the absence of $A, 3$ dps is zero error, hence
Initial count $=23-3=20 \mathrm{dps}$
After $10 \min =13-3=10 \mathrm{dps}$
After $20 \min =5 \mathrm{dps}$
$($ recorded $=5+3=8 \mathrm{dps})$
(50\% fall in $\left.10 \mathrm{~min}, T_{50}=10 \mathrm{~min}ight)$

A Geigger Muller counter is used to study the radioactive process. In the absence of radioactive substance…

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