How many components make up one compressor stage?

• A. 2 rotors
• B. 1 rotor + 1 stator
• C. 1 rotor
• D. 2 stators

Answer: (B)

A compressor stage is made up of a rotating blade set (rotor) and a stationary blade set (stator). The rotor spins and imparts energy to the air, increasing its velocity. The stator blades, which are fixed in the housing, then direct and convert that energy into higher static pressure by slowing and guiding the flow. This pairing—one rotor plus one stator—defines a single stage. If you had two rotors without a stator, you’d lose the necessary energy conversion and flow control that a stage requires; two stators alone wouldn’t add energy since there’s no moving blade to transfer energy to the air. So the best description of one compressor stage is one rotor plus one stator.