COMEDK 2025 Evening Solved Paper

Concept:Energy released in fission equals the increase in total binding energy from the parent nucleus to the fragments.Explanation:The parent nucleus is Radium with mass number $200$ and binding energy per nucleon $5.6\ \mathrm{MeV}$.Its total binding energy is: $200 \times 5.6 = 1120\ \mathrm{MeV}$.The two fragments are Cadmium ($A=112$) and Hassium ($A=108$), each with binding energy per nucleon $8.0\ \mathrm{MeV}$.Total binding energy of Cadmium: $112 \times 8.0 = 896\ \mathrm{MeV}$.Total binding energy of Hassium: $108 \times 8.0 = 864\ \mathrm{MeV}$.Sum of products' binding energies: $896 + 864 = 1760\ \mathrm{MeV}$.The energy released $Q$ is the gain in binding energy:$Q = (\text{total BE of products}) - (\text{total BE of parent})$$Q = 1760 - 1120 = 640\ \mathrm{MeV}$.Answer:$640\ \mathrm{MeV}$ (Option C).