152) If a heat pump cycle operates between the condenser temperature of +27°C and evaporator temperature of - 23°C, then the Carnot COP will be

153) A certain refrigerating system has a normal operating suction pressure of 10 kg/cm gauge and condensing pressure of about 67 kg/cm. The refrigerant used is

154) Aqua ammonia is used as refrigerant in the following type of refrigeration system

155) If the evaporator temperature of a plant is lowered, keeping the condenser temperature constant, the h.p. of compressor required will be

156) In a refrigeration cycle, the flow of refrigerant is controlled by