1

Define mass defect of a nucleus. Binding energy of $_{8}O_{16}$ is $127.5MeV$. Write the value of its 'binding energy per nucleon'. Write the value of $1eV$ energy in joule.

State the law of radioactive decay. Hence derive the expression $N=N_{0}e_{−λt}$ where symbols have their usual meanings.

(a) Write the characteristic properties of nuclear force.

(b) Draw a plot of potential energy of a pair of nucleons as a function of their separation. Write two important conclusions that can be drawn from the graph

(b) Draw a plot of potential energy of a pair of nucleons as a function of their separation. Write two important conclusions that can be drawn from the graph

Bombardment of Beryllium by alpha particles resulted in the discovery of :

(a) What do you mean by $Q$ value of a nuclear reaction?

(b) Write down the expression for $Q$ value in the class of $α$ decay.

(b) Write down the expression for $Q$ value in the class of $α$ decay.

Plot a graph showing the variation of undecayed nuclei $N$ versus time $t$. From the graph, find out how one can determine the half-life and average life of the radioactive nuclei.

Explain the principle and working of a nuclear reactor with the help of a labelled diagram.

Distinguish between nuclear fission and fusion. Show how in both these processes energy is released. Calculate the energy release in MeV in the deuterium-tritium fusion reaction :

$_{1}H+_{1}H→_{1}He+_{0}n_{1}$

Using the data:

$m(_{1}H)=2.014102u$

$m(_{1}H)=3.016049u$

$m(_{2}He)=4.002603u$

$mn=1.008665u$

$lu=931.5MeV/c2$

$_{1}H+_{1}H→_{1}He+_{0}n_{1}$

Using the data:

$m(_{1}H)=2.014102u$

$m(_{1}H)=3.016049u$

$m(_{2}He)=4.002603u$

$mn=1.008665u$

$lu=931.5MeV/c2$

Why nuclear fusion reaction is also called thermo-nuclear reaction?

Write symbolically the nuclear $β_{+}$ decay process of $_{6}C$. Is the decayed product X an isotope or isobar of ($_{6}C$)? Given the mass values m ($_{6}C$) = 11.011434 u and m (X) = 11.009305 u. Estimate the Q-value in this process.