The combustion chamber of a gas turbine:

• A. Increases the Density of the Compressed Air
• B. Must Be Water Cooled to Protect Against High Temperature
• C. Is Where Fuel Is Added to Air, and Burned
• D. Preheats the Combustion Air Before It Is Compressed

Answer: (C)

The combustion chamber’s main job is to add fuel to the high‑pressure air and burn it to release heat, producing hot, high‑energy gases that drive the turbine. After the air is compressed, fuel is introduced and burned in this chamber, and the resulting heat raises the gas temperature and energy content so the turbine can extract useful work from the flow.

Burning the fuel doesn’t increase the air’s density; in fact, the temperature rise lowers density, even though the pressure is kept high. The combustor isn’t typically water cooled; many turbines use air cooling or film cooling to protect its walls. Preheating the air before it is compressed isn’t how a gas turbine operates—the air is compressed first, then heated by combustion to generate the high-energy gases needed for power.