If in nuclear reactor using U²³⁵ as fuel, the power output is 4.8 MW, the number of fissions per second is:
(Energy released per fission of U²³⁵ = 200 MeV watts, 1 eV = 1.6 X 10^–19 J)

1. 1.5×10¹⁷           

2. 3×10¹⁹           

3. 1.5×10²⁵           

4. 3×10²⁵

The number of beta particles emitted by a radioactive substance is twice the number of alpha particles emitted by it. The resulting daughter is an:
1. Isobar of a parent.
2. Isomer of a parent.
3. Isotone of a parent.
4. Isotope of a parent.

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. \(17.3~\text{MeV}\)

Fusion reaction takes place at a higher temperature because:

Which of the following pairs of nuclei are isotones?

1. ${}_{34}{}^{74}\mathrm{Se},$ ${}_{31}{}^{71}\mathrm{Ca}$          

2. ${}_{42}{}^{92}\mathrm{Mo},$ ${}_{40}{}^{92}\mathrm{Zr}$

3. ${}_{38}{}^{81}\mathrm{Sr},$ ${}_{38}{}^{86}\mathrm{Sr}$             

4. ${}_{20}{}^{40}\mathrm{Ca},$ ${}_{16}{}^{32}\mathrm{S}$

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$\mathrm{\beta }$

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. $6.4\times {10}^{-13}$ $\mathrm{J}$

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

After two alpha decays and four beta(-ve) decays, the atomic number: