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13.Nuclei
medium
A radioactive sample has ${N_0}$ active atoms at $t = 0$. If the rate of disintegration at any time is $R$ and the number of atoms is $N$, then the ratio $ R/N$ varies with time as
A
B
C
D
Solution
(d) Rate $R = – \frac{{dN}}{{dt}}$ $ = \lambda \;{N_0}{e^{ – \lambda t}} = \lambda N$
==> $\frac{R}{N}$= $\lambda$ (constant)
$i.e.$ graph between $\frac{R}{N}$ and $t$, be a straight line parallel to the time axis.
Standard 12
Physics
Similar Questions
Match List $I$ (Wavelength range of electromagnetic spectrum) with List $II$ (Method of production of these waves) and select the correct option from the options given below the lists
| List $I$ | List $II$ |
| $(1)$ $700\, nm$ to $1\,mm$ | $(i)$ Vibration of atoms and molecules |
| $(2)$ $1\,nm$ to $400\, nm$ | $(ii)$ Inner shell electrons in atoms moving from one energy level to a lower level |
| $(3)$ $ < 10^{-3}\,nm$ | $(iii)$ Radioactive decay of the nucleus |
| $(4)$ $1\,mm$ to $0.1\,m$ | $(iv)$ Magnetron valve |
