Which statement correctly describes a rotor blade?

• A. Blades fixed on a spindle
• B. The exhaust nozzle
• C. Stationary blades
• D. The diffuser

Answer: (A)

Rotor blades are the rotating components of a turbine stage, mounted to the rotor disk (spindle) so they spin with the shaft. Their job is to extract energy from the high‑temperature gas and convert it into mechanical energy as the rotor turns. This is what distinguishes them from stationary blades, which are fixed in place in the stator to guide the flow rather than rotate. The exhaust nozzle directs the spent gas out of the engine, and the diffuser helps convert velocity into pressure further upstream. So the description of rotor blades as fixed on a spindle correctly captures their rotating, attached-to-the-shaft nature.