250+ TOP MCQs on Chemical Rocket Propellant – Results of Thermochemical Calculations and Answers

Rocket Propulsion Multiple Choice Questions & Answers on “Chemical Rocket Propellant – Results of Thermochemical Calculations”.

1. Dissociation of the reaction products __________ with the rise in the chamber temperature and _________ with the rise in chamber pressure of a chemical rocket engine.
a) increases, increases
b) decreases, increases
c) decreases, decreases
d) increases, decreases
Answer: d
Clarification: Higher chamber temperature results in higher dissociation of the reaction products. But the dissociation can be suppressed by an increase in the chamber pressure.

2. Which of the following is a highly refined form of kerosene used as rocket fuel?
a) RP-1
b) HMX
c) RDX
d) C-4
Answer: a
Clarification: RP-1 is a highly refined form of kerosene. It is short for Rocket Propellant-1 or Refined Petroleum-1. A part of RP-1 includes toxic and carcinogenic hydrazine.

3. Which of the following fuels were used in the first stage of Titan I?
a) RP-1
b) RDX
c) HMX
d) LH₂
Answer: a
Clarification: RP-1 fuel is used in the first stage of Titan 1. Other than that, it was also used in the first stages of Saturn V, Energeia, Saturn I and IB etc. It is a cheaper and less explosive alternative to LH₂.

4. The fuel which releases the most energy per unit mass of combustion is ____________
a) LH₂
b) RP-1
c) Kerosene
d) Methane
Answer: a
Clarification: Compared to hydrocarbon fuels, liquid hydrogen delivers most energy per unit mass of combustion. Any hydrocarbon fuel, when subjected to combustion produces more pollution than LH₂.

5. 1-methyl-1, 2-dicyclopropyl cyclopropane is also called as ____________
a) Syntin
b) Kerosene
c) RP-1
d) Jet fuel
Answer: a
Clarification: Syntin is a high-energy formulation briefly used in the upper stages of rockets developed by the Soviet Union. Its molecular formula is C₁₀H₁₆ and it is a mixture of 4 stereoisomers.

6. ____________ is not a metallic additive in rocket propellants.
a) Beryllium
b) Aluminum
c) Nitroglycerine
d) Boron
Answer: c
Clarification: Nitroglycerine is a dense, colorless, explosive liquid. Its chemical formula is C₃H₅N₃O₉. It is neither metallic nor an additive.

7. Knocking in spark-ignition internal combustion engines is not the same as ____________
a) detonation
b) pinging
c) pinking
d) pre-ignition
Answer: d
Clarification: Knocking and pre-ignition are two separate events. Knocking happens when the combustion of some of the air-fuel mixture doesn’t occur because of the propagation of flame front due to spark-plug ignition, but when one or more air-fuel mixture pockets explode outside the normal combustion front. Pre-ignition refers to the case in which combustion happens even before the spark-plug fires.

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