Short horizontal lines on pressure-enthalpy chart show__________________?

A. Constant pressure lines
B. Constant temperature lines
C. Constant total heat lines
D. Constant entropy lines

Ammonia is __________________?

A. Non-toxic
B. Non-inflammable
C. Toxic and non-inflammable
D. Highly toxic and inflammable

Mass flow ratio of NH3 in comparison to Freon-12 for same refrigeration load and same temperature limits is of the order of___________________?

A. 1 : 1
B. 1 : 9
C. 9 : 1
D. 1 : 3

Where does the lowest temperature occur in a vapour compression cycle ?

A. Condenser
B. Evaporator
C. Compressor
D. Expansion valve

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________________?

A. Ammonia
B. Carbon dioxide
C. Freon
D. Brine

Highest pressure encountered in a refrigeration system should be________________?

A. Critical pressure of refrigerant
B. Much below critical pressure
C. Much above critical pressure
D. Near critical pressure

If the evaporator temperature of a plant is lowered, keeping the condenser temperature constant, the h.p. of compressor required will be________________?

A. Same
B. More
C. Less
D. More/less depending on rating

Pick up the correct statement about giving up of heat from one medium to other in ammonia absorption system ?

A. Strong solution to weak solution
B. Weak solution to strong solution
C. Strong solution to ammonia vapour
D. Ammonia vapour to weak solution

Which of the following is not a desirable property of a refrigerant_________________?

A. High triiscibility with oil
B. Low boiling point
C. Good electrical conductor
D. Large latent heat

At lower temperatures and pressures, the latent heat of vaporisation of a refrigerant_________________?

A. Decreases
B. Increases
C. Remains same
D. Depends on other factors