4) The cycle of operation in a vapour compression refrigerator is

5) Number of solutions for the system of linear equations 2x-3y = 7, x-y = 8 is

6) A domestic refrigerator uses the following type of device for expansion

7) Freon leak can be detected by

8) In an office room of 200 sq ft floor area with 4 persons and 4 computers, the capacity of air conditioner required is minimum