Engineering Questions with Answers - Multiple Choice Questions

Rocket Propulsion – Liquid Monopropellants

1 - Question

Which of the following is a monopropellant?
a) H2
b) Diluted H2O2
c) Hydrazine
d) Monomethyl hydrazine
View Answer Answer: c
Explanation: Hydrazine can be used as a monopropellant. It can also be used as a storable fuel. Concentrated H2O2 is another example for a monopropellant.

2 - Question

__________ is not a method of monopropellant ignition.
a) Flame heat
b) Electrical
c) Catalytic material
d) Pulverization
View Answer Answer: d
Explanation: Pulverization for the sake of monopropellant ignition is not a possible method. Pulverization is the act of grinding a substance to powder or dust form.

3 - Question

___________ is an excellent catalyst for hydrazine at room temperature.
a) Zeolite
b) Iridium
c) Antimony trioxide
d) Cobalt
View Answer Answer: b
Explanation: Iridium is an excellent catalyst for hydrogen decomposition reaction at room temperature. For faster startup, the catalyst can be reheated.

4 - Question

Iron, nickel and cobalt can decompose hydrazine at ________ temperature.
a) 273 K
b) 289 K
c) 400 K
d) 450 K
View Answer Answer: d
Explanation: Hydrazine will be decomposed in the presence of iron, nickel or cobalt at elevated temperatures (about 450K). Here the temperature act as an agent for improving catalytic decomposition. Some of the other catalysts can do the same at room temperature.

5 - Question

In catalytic decomposition of hydrazine, it decomposes into ________ and _______
a) ammonia; nitrogen
b) hydrogen; nitrogen
c) ammonium; nitrogen
d) ammonia; hydrogen
View Answer Answer: a
Explanation: Hydrazine has a chemical formula of N2H4. It undergoes catalytic decomposition to give ammonia (NH3) and nitrogen (N2). Some forms of hydrazine include monomethyl hydrazine (MMH) and unsymmetrical dimethyl hydrazine (UDMH).

6 - Question

The catalytic decomposition of hydrazine is an __________ reaction.
a) endothermic
b) exothermic
c) endergonic
d) exergonic
View Answer Answer: b
Explanation: Exothermic reactions involve the release of heat to the surroundings. Hydrazine undergoing catalytic decomposition is an example of exothermic reaction.

7 - Question

Ammonia decomposition into nitrogen and hydrogen gases is an _________ reaction.
a) Endothermic
b) Exothermic
c) Endergonic
d) Exergonic
View Answer Answer: a
Explanation: The decomposition reaction in which nitrogen and hydrogen forms from ammonia is an endothermic reaction. In endothermic reactions, heat is absorbed from the surroundings for the reaction to take place.

8 - Question

Hydroxylammonium nitrate has a specific impulse of ___________
a) 300-365s
b) 10-65s
c) 200-265s
d) 100-165s
View Answer Answer: d
Explanation: Hydroxylammonium nitrate is an example of a synthetic monopropellant. It is abbreviated as HAN. It has a specific impulse in between 200 and 265s.

9 - Question

Standard commercial hydrazine has less than ________% aniline.
a) 0.5
b) 1.0
c) 0.8
d) 0.6
View Answer Answer: b
Explanation: Commercially available hydrazine has less than 1% aniline in it. It also has about 1.5% maximum weight of water and less than 10 mg/l of particulates, including carbon.

10 - Question

UDMH stands for _________
a) Unsymmetrical Dimethyl Hydrazine
b) Unsaturated Dimethyl Hydrazine
c) Unsymmetrical Diethyl Hydrazine
d) Unsaturated Diethyl Hydrazine
View Answer Answer: a
Explanation: UDMH is the short form of Unsymmetrical Dimethyl Hydrazine. Its chemical formula is (CH3)2NNH2. UDMH is often used instead of hydrazine because forms a more stable liquid at larger temperatures.

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