250+ TOP MCQs on Liquid Fuels and Answers

Rocket Propulsion Multiple Choice Questions on “Liquid Fuels”.

1. __________ is not liquid fuel.
a) Xylidine
b) Furfuryl alcohol
c) Hydrazine hydrate
d) Nitric acid
Answer: d
Clarification: Nitric acid is not a fuel, but and oxidizer. HNO₃ is also used as a very strong oxidizing agent in chemical reactions.

2. Which of the following is not a liquid fuel?
a) Ammonia
b) Ethyl alcohol
c) Borohydrides
d) Hydrogen peroxide
Answer: d
Clarification: Hydrogen peroxide (H₂O₂) acts as an oxidizer. Ammonia (NH₃), ethyl alcohol (C₂H₅OH), and Borohydrides (containing BH₄^–) are liquid fuels.

3. Petroleum derivatives are mainly ___________ chemicals.
a) hydrocarbon
b) gasoline
c) alcoholic
d) aldehydic
Answer: a
Clarification: Petroleum derivatives are hydrocarbon chemicals. This means that it is a compound made up of hydrogen and carbon.

4. Which of the following is not a hydrocarbon fuel?
a) Kerosene
b) Diesel
c) Turbojet fuel
d) Ethyl alcohol
Answer: d
Clarification: Ethyl alcohol is not a hydrocarbon fuel. Kerosene and diesel are petroleum derivatives.

5. Petroleum fuels form ________ radiating flames.
a) blue-green
b) orange-red
c) yellow-white
d) orange-yellow
Answer: c
Clarification: The bright brilliant radiating flames of petroleum fuels are yellow-white in color. Main examples of petroleum fuels include kerosene, gasoline, gaseous fuels like methane, propane, butane etc.

6. Carbon deposits on the inside of cooling passage can lead to __________
a) decrease in heat transfer and decrease in wall temperature
b) increase in heat transfer and decrease in wall temperature
c) decrease in heat transfer and increase in wall temperature
d) increase in heat transfer and increase in wall temperature
Answer: c
Clarification: Cooling passages by some means may have carbon deposits on its inside. This can lead to a decrease in heat transfer and an increase in the wall temperature. It happens because the operation of cooling passages is inhibited by the carbon deposits and as a result the cooling is ineffective.

7. Atlas, Delta and Thor rocket engines use __________ fuel along with liquid oxygen.
a) RP-1
b) RDX
c) HMX
d) H₂O₂
Answer: a
Clarification: RP-1 is used in Thor, Delta and Atlas rocket engines as a fuel. Oxidizer for this fuel is usually liquid oxygen. RP-1 is a highly refined form of kerosene.

8. Methane is a __________ fuel.
a) cryogenic hydrocarbon
b) monopropellant
c) bipropellant
d) hypergolic hydrocarbon
Answer: a
Clarification: Methane falls under the category of cryogenic hydrocarbon fuels. Using methane or RP-1 have shown to give a small advantage in the performance of initial stages of space launch vehicles.

9. RP-1 specific gravity at 15°C is __________
a) 0.80
b) 0.75
c) 0.70
d) 0.65
Answer: a
Clarification: RP-1 is a highly refined form of kerosene. It is alternatively called as Rocket Propellant-1 or Refined Petroleum-1. It has a specific gravity of 0.80 at a temperature of 15°C.

10. H₂ burns with oxygen with a ________ flame.
a) yellow-orange
b) yellow-white
c) colorless
d) blue-yellow
Answer: c
Clarification: When H₂ burns with oxygen, it produces a colorless flame. In reality, the flame is a pale blue that appears to be invisible in daylight.