Question

The main thermodynamic cycle used in a turbojet engine is

• A. Otto cycle
• B. Diesel cycle
• C. Brayton cycle
• D. Rankine cycle

Hint:

Common thermodynamic cycles: \[ \boxed{ \begin{aligned} \text{Otto Cycle} &\rightarrow \text{Petrol Engines} \text{Diesel Cycle} &\rightarrow \text{Diesel Engines} \text{Brayton Cycle} &\rightarrow \text{Gas Turbines / Turbojets} \text{Rankine Cycle} &\rightarrow \text{Steam Power Plants} \end{aligned} } \]

Answer 1

The Correct Option is C

Step 1: Recall the thermodynamic cycle of a turbojet engine. A turbojet engine operates on the \[ \boxed{\text{Brayton (Joule) Cycle}.} \] This cycle consists of
• Isentropic compression,
• Constant-pressure heat addition,
• Isentropic expansion,
• Constant-pressure heat rejection.

Step 2: Identify the correct cycle. Since gas turbine engines operate on the Brayton cycle, \[ \boxed{\text{Brayton cycle}} \] is the correct answer. Thus, \[ \boxed{(C)} \] is the correct answer.