Correct Answer : Reversibility
Explanation : For simple cases of nozzle expansion, the effects of friction, heat transfer, shock waves, non-equilibrium and divergence angle are neglected. But the process is considered to be reversible none the less.
Correct Answer : Option (C) : Syntin
Explanation : Syntin is a high-energy formulation briefly used in the upper stages of rockets developed by the Soviet Union. Its molecular formula is C10H16 and it is a mixture of 4 stereoisomers.
Correct Answer : Option (B) : LH2
Explaination : Compared to hydrocarbon fuels, liquid hydrogen delivers most energy per unit mass of combustion. Any hydrocarbon fuel, when subjected to combustion produces more pollution than LH2.
Correct Answer : Option (A) : RP-1
Explanation : RP-1 fuel is used in the first stage of Titan 1. Other than that, it was also used in the first stages of Saturn V, Energeia, Saturn I and IB etc. It is a cheaper and less explosive alternative to LH2.