$N$ atoms of a radioactive element emit $n$ number of $\alpha$-particles per second. Mean life of the element in seconds, is
$N$ atoms of a radioactive element emit $n$ number of $\alpha$-particles per second. Mean life of the element in seconds, is
- A
$\frac{n}{N}$
- B
$\frac{N}{n}$
- C
$0.693 \frac{N}{n}$
- D
$0.693 \frac{n}{N}$
Similar Questions
The sun radiates energy in all directions. The average radiations received on the earth surface from the sun is $1.4\;kilowatt/{m^2}$.The average earth- sun distance is $1.5 \times {10^{11}}metres$. The mass lost by the sun per day is($1$ day $= 86400$ seconds)
The sun radiates energy in all directions. The average radiations received on the earth surface from the sun is $1.4\;kilowatt/{m^2}$.The average earth- sun distance is $1.5 \times {10^{11}}metres$. The mass lost by the sun per day is($1$ day $= 86400$ seconds)
The graph in figure shows how the count-rate $A$ of a radioactive source as measured by a Geiger counter varies with time $t.$ The relationship between $A$ and $t$ is : $($ Assume $ln\,\, 12 = 2.6)$
The graph in figure shows how the count-rate $A$ of a radioactive source as measured by a Geiger counter varies with time $t.$ The relationship between $A$ and $t$ is : $($ Assume $ln\,\, 12 = 2.6)$
Curie is a unit of
Curie is a unit of
- [AIPMT 1989]
$37$ Rutherford equals
$37$ Rutherford equals
A radioactive sample with a half life of $1$ month has the label : “Activity$=2\, micro\,\,curies$ on $1-8-1991$.'' What will be its activity two months earlier ............ $micro\,\, curies$.
A radioactive sample with a half life of $1$ month has the label : “Activity$=2\, micro\,\,curies$ on $1-8-1991$.'' What will be its activity two months earlier ............ $micro\,\, curies$.
- [AIPMT 1988]