267) The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body. This statement is known as

268) An ordinary passenger aircraft requires a cooling system of capacity.

269) In air-conditioning of aeroplanes, using air as a refrigerant, the cycle used is

270) The thermal diffusivity for solids is generally less than those for liquids and gases.

271) Conduction is the process of heat transfer from one particle of the body to another by the actual motion of the heated particles.