Which of the following is not a desirable property of a liquid propellant?

Low specific gravity

Stability

Low freezing point

High specific heat

Correct Answer : Low specific gravity

Explanation : One of the desirable properties of a liquid propellant is that it should have high specific gravity. Specific gravity is the ratio of density of a substance to the density of a reference substance.

Recently Updated in Rocket Propulsion Questions

Use of solenoid valves increases power consumption for a cold gas propellant system.

True

False

Can Not Say

None of the above

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.

For a short period of operation (lasting few minutes), the gas expansion in cold gas systems is ________

adiabatic

isothermal

homogenous

heterogeneous

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.

Thrust in RCS is produced by the momentum exchange between exhaust and the _______

pump

injector

payload

spacecraft

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 = mV_e.