1.Vertical lines on pressure-enthalpy chart show constant

2.The COP of a vapour compression plant in comparison to vapour absorption plant is

3.Most of the domestic refrigerators work on the following refrigeration system

4.The C.O.P. of a refrigeration cycle with lowering of condenser temperature, keeping the evaporator temperature constant, will

5.For obtaining high COP, the pressure range of compressor should be