13. A nuclear reactor is said to have become 'critical' when A.It stops due to malfunctioning B.It starts emitting dangerous radioactive radiations C.It is shut down to avoid explosion D.It is ready to produce controlled energy
Option D Solution: To produce controlled energy i.e energy at a controlled or steady rate, the number of fissions per second must be controlled and maintained at that rate. Excess neutrons should be absorbed by control roads like cadmium.
