ρ= VM=34πR3mn×A=34πAR03mn×A
So ρ is almost is constant
$\begin{aligned}
& \mathrm{R}=\mathrm{R}_0 \mathrm{A}^{1 / 3} \
& \mathrm{R} \propto \mathrm{A}^{1 / 3}
\end{aligned}$
JEE Main 2025 — Physics Modern Physics
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : The density of the copper (2964Cu) nucleus is greater than that of the carbon (612C) nucleus.
Reason (R): The nucleus of mass number A has a radius proportional to A1/3.
In the light of the above statements, choose the most appropriate answer from the options given below :
Held on 7 Apr 2025 · Verified 6 Jul 2026.
(A) is correct but (R) is not correct
(A) is not correct but (R) is correct
Both (A) and (R) are correct and (R) is the correct explanation of (A)
Both (A) and (R) are correct but (R) is not the correct explanation of (A)
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Two $4$ bits binary numbers, $A = 1101$ and $B = 1010$ are given in the inputs of a logic circuit shown in figure below. The output $(Y)$ will be: 
Two radioactive substances A and B of mass numbers $200$ and $212$ respectively, shows spontaneous $\alpha$-decay with same $Q$ value of $1$ MeV. The ratio of energies of $\alpha$-rays produced by A and B is ________.
Using Bohr's model, calculate the ratio of the magnetic fields generated due to the motion of the electrons in the $2^{\text{nd}}$ and $4^{\text{th}}$ orbits of hydrogen atom _______.
The de Broglie wavelength for an electron accelerated through the potential difference of $V_1$ volt is $\lambda_1$. When the potential difference is changed to $V_2$ volt, the associated de Broglie wavelength is increased by $50\%$. If $(V_1/V_2) = (9/\alpha)$, then the value of $\alpha$ is __________.
The output $Y$ for the given inputs $A$ and $B$ to the circuit is: 
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