🔍 Key Concepts

• Basic thermodynamics: how heat energy is turned into mechanical work • The role of a turbine in an engine or power plant cycle • The functions of a condenser and an air ejector in a steam or refrigeration system

💭 Think About

• Which device in the list actually has moving parts that produce rotation or motion directly from expanding steam or gas? • Do condensers and air ejectors mainly create motion, or do they mainly support pressure/temperature conditions in the system? • In a typical steam power plant, at which component is the energy in high‑temperature, high‑pressure steam first turned into shaft rotation?

✅ Before You Answer

• Identify which option’s primary purpose is to change heat energy into shaft or rotational energy • Confirm which components mainly support the cycle by removing heat or air, rather than doing mechanical work output • Make sure you are not confusing "necessary for the cycle" with "directly converts thermal to mechanical energy"