A device in which some portion of waste heat of flue gases is recovered to heat the air before it passes to the furnace for combustion purpose, is knwon as

The internal flue tubes of a Lancashire boiler are reduced in diameter at the back to provide access to the lower part of the boiler.

For maximum discharge through a chimney, the temperature of flue gases inside the chimney should the slightly more than the atmospheric temperature.

The efficiency of the plant __________ with the mechanical draught.

The function of a governor is to keep the engine speed uniform at all load conditions.