The mass of a nucleus is \(0.042~\text{u}\) less than the sum of the masses of all its nucleons. The binding energy per nucleon of the nucleus is near:
1. \(4.6~\text{MeV}\)
2. \(5.6~\text{MeV}\)
3. \(3.9~\text{MeV}\)
4. \(23~\text{MeV}\)
If \(M(A,~Z)\), \(M_p\), and \(M_n\) denote the masses of the nucleus \(^{A}_{Z}X,\) proton, and neutron respectively in units of \(u\) (\(1~u=931.5~\text{MeV/c}^2\)) and represent its binding energy \((BE)\) in \(\text{MeV}\). Then:
1. | \(M(A, Z) = ZM_p + (A-Z)M_n- \frac{BE}{c^2}\) |
2. | \(M(A, Z) = ZM_p + (A-Z)M_n+ BE\) |
3. | \(M(A, Z) = ZM_p + (A-Z)M_n- BE\) |
4. | \(M(A, Z) = ZM_p + (A-Z)M_n+ \frac{BE}{c^2}\) |
Two nuclei have their mass numbers in the ratio of \(1:3.\) The ratio of their nuclear densities would be:
1. \(1:3\)
2. \(3:1\)
3. \((3)^{1/3}:1\)
4. \(1:1\)
The binding energy of deuteron is \(2.2~\text{MeV}\) and that of \(_2\mathrm{He}^{4}\) is \(28~\text{MeV}\). If two deuterons are fused to form one \(_{2}\mathrm{He}^{4}\), then the energy released is:
1. \(25.8~\text{MeV}\)
2. \(23.6~\text{MeV}\)
3. \(19.2~\text{MeV}\)
4. \(30.2~\text{MeV}\)
The Binding energy per nucleon of \(^{7}_{3}\mathrm{Li}\) and \(^{4}_{2}\mathrm{He}\) nucleon are \(5.60~\text{MeV}\) and \(7.06~\text{MeV}\), respectively. In the nuclear reaction \(^{7}_{3}\mathrm{Li} + ^{1}_{1}\mathrm{H} \rightarrow ^{4}_{2}\mathrm{He} + ^{4}_{2}\mathrm{He} +Q\), the value of energy \(Q\) released is:
1. \(19.6~\text{MeV}\)
2. \(-2.4~\text{MeV}\)
3. \(8.4~\text{MeV}\)
4. \(17.3~\text{MeV}\)
The energy equivalent of \(0.5\) g of a substance is:
1. \(4.5\times10^{13}\) J
2. \(1.5\times10^{13}\) J
3. \(0.5\times10^{13}\) J
4. \(4.5\times10^{16}\) J
The gravitational force between H-atom and another particle of mass m will be given by Newton's law \(F=\frac{GMm}{r^2},\) where r is
in km and
1. | M=mproton+melectron. |
2. | M=mproton+melectron-\(\frac{B}{c^2}\) ( B=13.6 eV ). |
3. | M is not related to the mass of the hydrogen atom. |
4. | M=mproton+melectron-\(\frac{|V|}{c^2}\) ( |V| = magnitude of the potential energy of electron in the H-atom). |
When a nucleus in an atom undergoes a radioactive decay, the electronic energy levels of the atom:
1. | do not change for any type of radioactivity |
2. | change for α and β -radioactivity but not for γ -radioactivity |
3. | change for α -radioactivity but not for others |
4. | change for β -radioactivity but not for others |
Tritium is an isotope of hydrogen whose nucleus triton contains 2 neutrons and 1 proton. Free neutrons decay into . If one of the neutrons in Triton decays, it would transform into He3 nucleus. This does not happen. This is because;
1. | triton energy is less than that of a He3 nucleus |
2. | the electron created in the beta decay process cannot remain in the nucleus |
3. | both the neutrons in Triton have to decay simultaneously resulting in a nucleus with 3 protons, which is not a He3 nucleus. |
4. | free neutrons decay due to external perturbations which is absent in Triton nucleus |