74.
Evaporative cooling process employs a combination of cooling and humidification in which the

76.
A furnace is made of a refractory brick wall of thickness 0.5 metre and thermal conductivity 0.7 W/m.°K For the same temperature drop and heat loss, this refractory wall can be replaced by a layer of diatomaceous earth of thermal conductivity 0.14 W/m.K and thickness __________ metre.

80.
Multistage compression is necessary for high efficiency,