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

The binding energy $(BE)$ per nucleon for an element is $7.14 \text{ MeV}$. If the total $BE$ of the element is $28.6 \text{ MeV}$, then the number of nucleons in the element is:

The figure shows a plot of binding energy per nucleon $E_b$ against the nuclear mass $M$. $A, B, C, D, E, F$ correspond to different nuclei. Consider four reactions:
$(i) \, A + B \to C + \varepsilon$
$(ii) \, C \to A + B + \varepsilon$
$(iii) \, D + E \to F + \varepsilon$
$(iv) \, F \to D + E + \varepsilon$
where $\varepsilon$ is the energy released. In which reactions is $\varepsilon$ positive?

If a $H_2$ nucleus (deuteron) is completely converted into energy,the energy produced will be around .......... $MeV$.

The dependence of binding energy per nucleon,$B_N$ on the mass number,$A$,is represented by

The binding energy per nucleon of a nucleus ${}_Z X^A$ at rest is $6 \ MeV$. It undergoes $\beta^-$ decay as shown below:
${}_Z X^A \to {}_{Z+1} Y^A + {}_{-1}^0 e + \bar{\nu}$
The total kinetic energy $(K.E.)$ of the products is $3 \ MeV$. The binding energy per nucleon of $Y$ (in $MeV$) is: