Consider the following statements:
- 1. Aluminium powder is used as a solid fuel for rocket engines.
- 2. Compared to liquid fuel propelled rocket engines, the thrust per amount of fuel burned is higher in solid fuel propelled rocket engines.
Which of the statements given above is/are correct?
1 only
2 only
Both 1 and 2
Neither 1 nor 2
Answer is Right!
Answer is Wrong!
This question was previously asked in
UPSC CAPF – 2022
Statement 2: Compared to liquid fuel propelled rocket engines, the thrust per amount of fuel burned is higher in solid fuel propelled rocket engines. This statement is incorrect. “Thrust per amount of fuel burned” is related to specific impulse (Isp), which measures the efficiency of a rocket engine. High-performance liquid propellants (like liquid hydrogen and liquid oxygen) generally yield higher specific impulse than typical solid propellants. A higher specific impulse means more thrust is produced per unit of propellant mass flow rate, or equivalently, a given amount of fuel produces thrust for a longer time. While solid rockets can provide high thrust for short periods and are simpler, their efficiency in terms of thrust generated per unit mass of fuel consumed is usually lower than optimized liquid systems.
– Specific impulse (Isp) is a measure of rocket engine efficiency, representing thrust per unit weight flow rate of propellant, or exhaust velocity.
– Liquid propellants, especially cryogenic ones like LH2/LOX, generally achieve higher specific impulse than solid propellants.
– Higher specific impulse means more thrust generated per amount of fuel burned (by mass).