NEET Physics: Physics - Nuclear Physics questions with solutions

Q1. When the reactor shuts down why does it require cooling?

1. To cool the reactor from chain reaction
2. To cool the reactor from fission reaction
3. Both (1) and (2)
4. None of these

Answer: To cool the reactor from fission reaction

When a reactor shuts down, the self-sustaining chain reaction is stopped, but the fuel still contains radioactive fission products that continue to release heat. That residual heat is why cooling is still required.

Q2. One of the characteristics of nuclear reactions is that in their decayed or fused parts

1. total mall number keeps on changing
2. total charge number keeps on changing
3. total charge number remains constant
4. all the above

Answer: total charge number remains constant

Nuclear reactions can change the arrangement of nucleons, but they must conserve electric charge. Since charge is determined by the number of protons, the total charge number stays the same before and after the reaction.