151. The evaporator used in house-hold refrigerators is
152. The drier in a refrigeration system removes moisture in the system.
153. The __________ point of ammonia is -77.7°C.
154. Sulphur dioxide has the lowest boiling point.
155. For a given dry bulb temperature, as the relative humidity __________ the wet bulb temperature will increase.
156. The lowest thermal diffusivity is of
157. A low wet bulb temperature indicates very __________ humidity.
158. The operating temperature of a cold storage is - 2° C. The heat leakage from the surrounding is 30 kW for the ambient temperature of 40° C. The actual C.O.P. of refrigeration plant used is one fourth that of ideal plant working between the same temperatures. The power required to drive the plant is
159. In chemical dehumidification process,
160. A one tonne refrigerating machine means that
161. The air cooling system mostly used in transport type aircrafts is
162. The critical thickness of insulation is the ratio of thermal conductivity of the insulating material (k) to the heat transfer coefficient at the outer surface of the insulation (h0).
163. In counter-current flow heat exchanger, the logarithmic temperature difference between the fluids is __________ as compared to parallel flow heat exchanger.
164. Environmental protection agencies advice against the use of chloro-fluoro-carbon refrigerants since
165. When the lower temperature of a refrigerating machine is fixed, then the coefficient of performance can be improved by
166. The refrigerant carbon dioxide is not widely used because of its __________ power require ments per tonne of refrigeration and high operating pressures.
167. The by-pass factor of a cooling coil decreases with
168. Dehydration is the process of removing water vapour from the surrounding air.
169. The cooling of air, without any change in its specific humidity, is known as sensible cooling.
170. The capacity of the cooling tower and spray ponds __________ as the wet bulb temperature of air decreases.
171. A mixture of dry air and water vapour, when the air has diffused the maximum amount of water vapour into it, is called
172. The total pressure exerted by the mixture of air and water vapour is equal to the sum of pressures which each constituent would exert, if it occupied the same space by itself. This statement is called
173. The expansion valve in a refrigerator controls the flow of refrigerant.
174. Upto the critical radius of insulation,
175. The relative humidity lines on a psychrometric chart are