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

• 1. strong solution to weak solution
• 2. weak solution to strong solution
• 3. strong solution to ammonia vapour
• 4. ammonia vapour to weak solution

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

• 1. high triiscibility with oil
• 2. low boiling point
• 3. good electrical conductor
• 4. large latent heat

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

• 1. decreases
• 2. increases
• 3. remains same
• 4. depends on other factors

Question: Formation of frost on evaporator in refrigerator ________________?

• 1. results in loss of heat due to poor heat transfer
• 2. increases heat transfer rate
• 3. is immaterial
• 4. can be avoided by proper design

Question: In a refrigeration system, heat absorbed in comparison to heat rejected is_________________?

• 1. more
• 2. less
• 3. same
• 4. more for small capacity and less for high capacity

Question: One of the purposes of sub-cooling the liquid refrigerant is to________________?

• 1. reduce compressor overheating
• 2. reduce compressor discharge temperature
• 3. increase cooling effect
• 4. ensure that only liquid and not the vapour enters the expansion (throttling) valve

Question: Highest temperature encountered in refrigeration cycle should be________________?

• 1. near critical temperature of refrigerant
• 2. above critical temperature
• 3. at critica. temperature
• 4. much below critical temperature

Question: Absorption system normally uses the following refrigerant___________________?

• 1. Freon-11
• 2. Freon-22
• 3. C02
• 4. ammonia

Question: In a vapor compression cycle, the refrigerant immediately after expansion valve is___________________?

• 1. liquid
• 2. sub-cooled liquid
• 3. saturated liquid
• 4. wet vapour

Question: Choose the correct statement?

• 1. A refrigerant should have low latent heat
• 2. If operating temperature of system is low, then refrigerant with low boiling point should be used
• 3. Precooling and subcooling bf refrigerant are same
• 4. Superheat and sensible heat of a. refrigerant are same