The stable nucleus that has a radius half of the radius of $F{e}^{56}$ is:

1. $L{i}^7$ 

2. $N{a}^{21}$

3. $S^{16}$

4. $C{a}^{40}$

Which of the following is used as a moderator in nuclear reactors? 

1. Plutonium 

2. Cadmium 

3. Heavy water

4. Uranium 

The binding energy per nucleon of deuterium and helium atom is 1.1 MeV and 7.0 MeV. If two deuterium nuclei fuse to form a helium atom, the energy released is:

1. 19.2 MeV

2. 23.6 MeV

3. 26.9 MeV 

4. 13.9 MeV

A nuclear reaction along with the masses of the particle taking part in it is as follows;

$A + B \to C + D + Q MeV$
$1.002 1.004 1.001 1.003$
$amu amu amu amu$

The energy Q liberated in the reaction is:

1. 1.234 MeV

2. 0.931 MeV

3. 0.465 MeV

4. 1.862 MeV

In the reaction

${}_1{}^2\mathrm{H}+$ ${}_1{}^3\mathrm{H}$ $\to$ ${}_2{}^4\mathrm{He}$ $+$ ${}_0{}^1\mathrm{n}$, 
if the binding energies of ${}_1{}^2\mathrm{H},$ ${}_1{}^3\mathrm{H},$ $\mathrm{and}$ ${}_2{}^4\mathrm{He}$ are respectively a, b, and c (in MeV), then the energy in (MeV) released in this reaction is:

1.  c + a - b

2.  c - a - b

3.  a + b + c

4.  a + b - c

The energy equivalent of one atomic mass unit is:

1. $1.6\times {10}^{-19}$ $J$ 

2. $6.02\times {10}^{23}$ $J$

3. 931 MeV 

4. 9.31 MeV

In nuclear reaction ${}_2{}^4\mathrm{He}+{}_{\mathrm{Z}}{}^{\mathrm{A}}\mathrm{X}\to {}_{\mathrm{Z}+2}{}^{\mathrm{A}+3}\mathrm{Y}+\mathrm{B}$, \(\mathrm {B}\) denotes:

1. Electron           

2. Positron

3. Proton               

4. Neutron

If an electron and a positron annihilate, then the energy released is:

1. $3.2\times {10}^{-13}$ $\mathrm{J}$       

2. $1.6\times {10}^{-13}$ $\mathrm{J}$

3. $4.8\times {10}^{-13}$ $\mathrm{J}$           

4. $6.4\times {10}^{-13}$ $\mathrm{J}$

An atomic nucleus ${}_{90}{}^{232}\mathrm{Th}$ emits several $\mathrm{\alpha }$ and $\mathrm{\beta }$ radiations and finally reduces to ${}_{82}{}^{208}\mathrm{Pb}$. It must have emitted:
1. 4$\mathrm{\alpha }$ and 2$\mathrm{\beta }$             
2. 6$\mathrm{\alpha }$ and 4$\mathrm{\beta }$
3. 8$\mathrm{\alpha }$ and 24$\mathrm{\beta }$           
4. 4$\mathrm{\alpha }$ and 16$\mathrm{\beta }$

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. \(17.3~\text{MeV}\)