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
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
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
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
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
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
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
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
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
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
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.