49) In nuclear power plants, due to reflector, less fuel is needed to generate sufficient neutrons to sustain a chain reaction.

50) The secondary fuel used in nuclear power plants is

51) Theoretically, a four stroke cycle engine should develop __________ power as that of a two stroke cycle engine.

52) Light weight substances can not be effective moderators.

53) The higher combustion chamber wall temperature in compression ignition engines will __________ knocking tendency.