Before combustion can occur, the combustion air must be delivered to the combustor at a high-pressure and low-velocity. High-velocity, low-pressure air is converted to high-pressure, low-velocity air at what part of a centrifugal type compressor?

Correct Answer: Option B — Diffuser.

The diffuser is the critical component in a centrifugal compressor that converts the high-velocity, low-pressure air exiting the impeller into high-pressure, low-velocity air. By gradually increasing the flow area, the diffuser slows the air, effectively converting kinetic energy into static pressure, which is essential for efficient combustion.