Reaction : $\begin{aligned}
& 3{ }2^4 \mathrm{He} \longrightarrow{ }6^{12} \mathrm{C}+\gamma \text { rays } \
& \text { Mass defect }=\Delta \mathrm{m}=\left(3 \mathrm{~m}{\mathrm{He}}-\mathrm{m}{\mathrm{C}}\right) \
& =(3 \times 4.002603-12)=0.007809 \mathrm{u}
\end{aligned}Energyreleased=931 \Delta \mathrm{m} \mathrm{MeV}=7.27 \mathrm{MeV}=727 \times 10^{-2} \mathrm{MeV}$