Q. Using a nuclear counter the count rate of emitted particles from a radioactive source is measured. At t = 0 it was 1600 counts per second and t = 8 seconds it was 100 counts per second. The count rate observed, as counts per second, at t = 6 seconds is close to :

Solution:

at t = 0, $A_0 = \frac{dN}{dt} = 1600 C/s$
at t = 8s, A = 100 C/s
$\frac{A}{A_0} = \frac{1}{16} $ in 8 sec
Therefor half life is $t_{1/2} = 2 \; \sec$
$\therefore$ Activity at t = 6 will be $1600 ( \frac{1}{2} )^3$
= 200 C/s
$\therefore$ correct answer is (3)

You must select option to get answer and solution

Questions from JEE Main 2019

Physics Most Viewed Questions

5. The spectrum of an oil flame is an example for ...........

KCET 2010 Dual Nature Of Radiation And Matter