GATE Propulsion: Rockets: thrust equation, specific impulse, multi-staging, solid and liquid propellant rockets – Previous Year Questions

12 GATE previous year questions on Rockets: thrust equation, specific impulse, multi-staging, solid and liquid propellant rockets (Propulsion, Aerospace Engineering) with answers and explanations, from every paper.

1. GATE 2021 AE Q18 (1 mark, Multiple choice) – A rocket produces 25 MN thrust for 150 s with specific impulse 2980 N s/kg. Propellant consumed is approximately
2. GATE 2021 AE Q54 (2 marks, Numerical answer) – Hot gases at 2100 K and 14 MPa expand ideally to 0.1 MPa through a convergent-divergent nozzle of throat area 0.1 m². Molecular mass is 22 kg/kmol,…
3. GATE 2022 AE Q23 (1 mark, Multiple choice) – The region of highest static temperature in a rocket engine and the region of highest heat flux are , respectively.
4. GATE 2022 AE Q47 (2 marks, Multiple select) – A rocket at absolute chamber pressure 20 bar produces thrust F 1. Its hot exhaust is optimally expanded to 1 bar through a convergent-divergent nozzle…
5. GATE 2023 AE Q35 (1 mark, Numerical answer) – A ramjet vehicle flies at 1000 m/s, burns hydrogen of heat value 120 MJ/kg, and has overall efficiency 40% (propulsive power/heat release). With g…
6. GATE 2023 AE Q38 (2 marks, Multiple choice) – Two missiles have equal specific impulse and initial mass 5600 kg. A burns 120 kg/s for 30 s; B burns 70 kg/s for 70 s. Neglect gravity and drag.…
7. GATE 2023 AE Q65 (2 marks, Numerical answer) – A cryogenic expander-cycle rocket burns hydrogen at 32 kg/s and oxygen with m O 2/ m H 2=8. At stoichiometry with negligible reverse reaction, water…
8. GATE 2026 AE Q39 (2 marks, Multiple choice) – An ideal rocket has characteristic exhaust velocity of 1200 m/s, mass flow rate of 75 kg/s, thrust coefficient of 1.5, and nozzle throat area of 0.025…
9. GATE 2026 AE Q41 (2 marks, Multiple choice) – Consider a launch vehicle of mass 10 tons being launched vertically. The vehicle has 8 tons of propellant, which burns completely at a constant rate…
10. GATE 2025 AE Q32 (1 mark, Multiple choice) – An ideal two-stage rocket has identical specific impulse and structural coefficient for its two stages. For an optimized rocket, the two stages have…
11. GATE 2025 AE Q63 (2 marks, Numerical answer) – A monopropellant liquid rocket engine has 800 injectors of diameter 4 mm each, and with a discharge coefficient of 0.65. The liquid propellant of…
12. GATE 2024 AE Q57 (2 marks, Numerical answer) – A chemical rocket with an ideally expanded flow through the nozzle produces 5 106 N thrust at sea level. The specific impulse of the rocket is 200 s…