AFJROTC Commercial and General Aviation Take Off Practice Exam

In which type of jet propulsion does the thrust solely come from jet exhaust?

1. Hybrid propulsion

2. Pure jet

3. Turboprop

4. Turbofan

The correct answer is: Pure jet

The correct answer is pure jet propulsion because, in this type of system, the engine generates thrust exclusively from the expulsion of high-speed jet exhaust. In pure jet engines, such as turbojets, the air is compressed, mixed with fuel, and ignited. The resulting high-pressure exhaust gases are then expelled through a nozzle at high velocity, creating thrust according to Newton's third law of motion. This means that all the propulsive force comes from the jet's exhaust rather than any additional components or systems. Other propulsion types, such as turbofans and turboprops, utilize jet exhaust for thrust but also incorporate fans or propellers to enhance performance and efficiency. Hybrid propulsion combines aspects of differing propulsion methods, often involving both electric and traditional combustion engines, but it doesn't rely solely on jet exhaust for thrust. Since pure jet propulsion is characterized solely by generating thrust from the jet exhaust, it stands out as the clear answer.