In a gas turbine engine, the area where gases reach their maximum velocity is the

• A. Exhaust area nozzle
• B. Intake lip
• C. Combustion chamber
• D. Turbine disk

Answer: (A)

The key idea is that the gases gain most of their speed as they expand through the exhaust nozzle. After combustion and turbine stages have set up high pressure, the hot gases expand and convert pressure energy into kinetic energy as they pass through the nozzle. The nozzle shapes and accelerates the flow so that the gas exits the engine at its highest velocity, producing the jet thrust that propels the aircraft.

The intake lip mainly manages air entry, not rapid acceleration. The combustion chamber raises pressure and temperature but the flow hasn’t yet reached its maximum speed there. The turbine disk extracts energy to drive the compressor, which tends to slow the flow rather than maximize its speed. Therefore, the exhaust nozzle is the region where the gases achieve their maximum velocity.