Q1: Which of the following is not used as a fuel in rocket propellaht ?

ANS:B - Liquid oxygen

Kerosene oil is not typically used as a fuel in rocket propulsion systems. Explanation:

1. Liquid Hydrogen: Liquid hydrogen is commonly used as a fuel in rocket propulsion systems, particularly in combination with liquid oxygen as an oxidizer. It offers high specific impulse and is commonly used in cryogenic rocket engines, such as those used in the Space Shuttle and some stages of the Saturn V rocket.
2. Liquid Oxygen: Liquid oxygen serves as an oxidizer in many rocket propulsion systems. It supports combustion by providing the oxygen required for the fuel to burn efficiently. Liquid oxygen is often used in combination with liquid hydrogen, kerosene, or other fuels.
3. Liquid Hydrazine: Liquid hydrazine is used as a monopropellant or a component of bipropellant systems in some rocket engines. It is hypergolic, meaning it spontaneously ignites upon contact with an oxidizer, such as nitrogen tetroxide. Liquid hydrazine is commonly used in satellite propulsion systems and maneuvering thrusters.
4. Kerosene Oil: While kerosene oil is used as a fuel in various applications, including jet engines and some liquid-fueled rocket engines, it is not as commonly used in modern rocket propulsion systems as liquid hydrogen, liquid oxygen, or liquid hydrazine. Kerosene-based rocket engines, such as the RD-180 used in the Atlas V rocket, do exist, but they are not as prevalent as engines using other propellants.