Rocket Propulsion Questions and Answers – Liquid Propellants

This set of Rocket Propulsion Multiple Choice Questions & Answers (MCQs) focuses on “Liquid Propellants”.

1. What kind of propulsion is used for trajectory adjustments and attitude corrections?
a) Boosting propulsion
b) Auxiliary propulsion
c) Sustaining propulsion
d) Cryogenic propulsion
View Answer

Answer: b
Explanation: Auxiliary propulsion helps in trajectory adjustments and attitude corrections. Boosting propulsion imparts a high velocity to the payload. Boosting and auxiliary propulsion are one way of classifying liquid rocket engines.

2. How are liquid rocket engines classified on the basis of their feed system?
a) Pressurized or turbopump
b) Restartable or single fired
c) Single flight or reusable
d) Boosting or auxiliary
View Answer

Answer: a
Explanation: Feed system is used for the transfer of the liquid propellants from their storage tank to the thrust chamber of the rocket engine. They can be a gas-pressurized feed system or turbo pump feed system.

3. The thruster is also called as _____________
a) combustion chamber
b) thrust chamber
c) nozzle
d) injector
View Answer

Answer: b
Explanation: Thruster is the same as the thrust chamber of a rocket engine. It is the combination of the injector, combustion chamber and the nozzle.

4. Which of the following ways of thrust chamber cooling may use niobium metal?
a) Film cooling
b) Cooling jacket
c) Radiation cooling
d) Ablative cooling
View Answer

Answer: c
Explanation: Niobium is a special high temperature material that can radiate excess heat. So it is used as part of the radiation cooling of the thrust chamber.

5. At what temperature are the liquid oxygen and the liquid hydrogen kept in their storage tanks of the cryogenic rocket engine?
a) -253°C and -183°C
b) -183°C and -253°C
c) -253°C for both
d) -183°C for both
View Answer

Answer: b
Explanation: Liquid oxygen is stored at -183°C and liquid hydrogen is stored at -253°C. Extensive care is taken to ensure that the vaporization losses are minimized for the cryogenic propellants.
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6. Determine the mixture ratio if mass flow rate of the oxidizer is 3/4 times the total mass flow rate of the combustion products.
a) 2.5
b) 3
c) 2
d) 1
View Answer

Answer: b
Explanation: Assuming the combustion gases are purely a result of the propellants and using mass conservation, mcomb = mo + mf.
mo = 3/4 mcomb
So, mf = 1/4 mcomb
Mixture ratio r = mo / mf = 3.

7. If the total propellant flow rate is 24 kg/s and the mixture ratio is 2.3, determine the mass flow rate of the oxidizer.
a) 19.67 kg/s
b) 15.33 kg/s
c) 12.94 kg/s
d) 16.73 kg/s
View Answer

Answer: d
Explanation: mo = r m/(r+1)
= 2.3 x 24/(3.3) = 16.73 kg/s.

Sanfoundry Global Education & Learning Series – Rocket Propulsion.

To practice all areas of Rocket Propulsion, here is complete set of 1000+ Multiple Choice Questions and Answers.


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Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

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