equal to one

greater than one

less than one

equal to Nusselt number

is black in colour

absorbs heat radiations of all wave lengths falling on it

reflects all the heat radiations

transmits the heat radiations

the mass of water vapour present in 1 m³ of dry air

the mass of water vapour present in 1 kg of dry air

the ratio of the actual mass of water vapour in a unit mass of dry air to the mass of water vapour in the same mass of dry air when it is saturated at the same temperature and pressure.

the ratio of actual mass of water vapour in a given volume of moist air to the mass of water vapour in the same volume of saturated air at the same temperature and pressure

equal to

less than

greater than

none of these

compressor

condenser

evaporator

expansion valve