Correct Answer : Nitric acid
Explanation : Nitric acid is not a fuel, but and oxidizer. HNO3 is also used as a very strong oxidizing agent in chemical reactions.
Correct Answer : Option (B) : False
Explanation : In order to decrease power consumption, one can use solenoid valves. It requires an electric pulse to open and close and hence can be easily controlled with lesser power expended.
Correct Answer : Option (A) : adiabatic
Explanation : Since the operation lasts only a short period of time, the expansion can be taken as adiabatic. It means that there is no heat absorption or release by the gas.
Correct Answer : Option (D) : spacecraft
Explanation : Thrust generation is due to the exchange of momentum between exhaust and the spacecraft. The thrust is given by Newton’s second law F = mVe.
