Q 12-13-041JEE MainJEE Main 2024 (1 Feb, Shift 1)Easy
The radius of a nucleus of mass number 64 is $4.8$ fermi. Then the mass number of another nucleus having radius of $4$ fermi is $\dfrac{1000}{x}$, where $x$ is ______.
Numerical value type. Enter your answer.
Answer: 27
$R \propto A^{1/3}$, so
$$A = 64\left(\frac{4}{4.8}\right)^3 = 64\times\frac{125}{216} = \frac{1000}{27} \Rightarrow x = 27$$
Solution by Sreeraj P, M.Sc Physics