262) The process of heat transfer from one particle of the fluid to another by the actual movement of the fluid particles caused by some mechanical means, is known as

263) When ? is absorptivity, ? is reflectivity and ? is transmittivity, then for a diathermanous body,

264) When there is an addition of water vapour to the air of enclosed space, a gain in __________ is said to occur.

265) The relative humidity __________ as air gets drier.

266) The central air conditioning system has __________ overall efficiency as compared to individual systems.