VAPOR ABSORPTION REFRIGERATION

MULTIPLE CHOICE QUESTIONS

WITH ANSWERS (MCQ) 

Vapor absorption refrigeration is like a

vapor compression system. The

means of compression are different. It

causes refrigeration from heat.

1. Vapor absorption refrigeration uses

(a) Mechanical energy
(b) Electric energy
(c) Kinetic energy
(d) None
(Ans: d)

2. Vapor absorption refrigeration uses

(a) Mechanical energy
(b) Electric energy
(c) Heat energy
(d) None
(Ans: c)

3. Vapor absorption refrigeration uses

(a) Potential energy
(b) Datum energy
(c) Kinetic energy
(d) None
Ans: (d)

4. Vapor absorption refrigeration system only moving part is

(a) Compressor
(b) Pump
(c) Turbine
(d) None
(Ans: b)

5. Electrolux refrigerator uses

(a) Hydrogen + water
(b) Hydrogen + ammonia
(c) Hydrogen + water + Ammonia
(d) None
(Ans: c)

6. Which system is less noisy in operation

(a) Gas refrigeration
(b) Vapor Compression refrigeration
(c) Vapor absorption refrigeration
(d) None
(Ans: c)

7. After cooling of aqua solution in the aqua heat exchanger, the concentration of ammonia

(a) Remains the same
(b) Increase
(c) Decrease
(d) None
(Ans: a)

8. Ammonia water absorption system achieves

(a) Temperatures > 0⁰C
(b) Temperatures < 0⁰C
(c)  = 0⁰C
(d) None
(Ans: b)

9. Water Lithium bromide vapor absorption achieves

(a) Temperatures > 0⁰C
(b) Temperatures < 0⁰C
(c)  = 0⁰C
(d) None
(Ans: a)

10. There is change of phase of refrigerant in

(a) Gas refrigeration
(b) Vortex-tube refrigeration
(c) Vapor absorption Refrigeration
(d) None
(Ans: c)

11. The ratio of boiling point of refrigerant & boiling point of absorbent should be

(a) > 1

(b) < 1

(c) = 1

(d) None

(Ans: b)

12. COP of a vapor absorption refrigeration is

(a) >1

(b) < 1

(c) = 1

(d) None

(Ans: b)

13. Which system uses Rectifier?

(a) In a ammonia water vapor absorption refrigeration system

(b) Water lithium bromide vapor absorption refrigeration system

(c) Electrolux Refrigerator

(d) None

(Ans: a)

14. Use of air cooled rectifier exists

(a) In a ammonia water vapor absorption refrigeration system

(b) Water lithium bromide vapor absorption refrigeration system

(c) Electrolux Refrigerator

(d) None

(Ans: d)

  15. Air cooled Condenser exists in a

(a)  Ammonia water vapor absorption refrigeration system

(b) Water lithium bromide vapor absorption refrigeration system

(c) Electrolux Refrigerator

(d) None

(Ans: c)

    16. The maximum capacity of a single vapor absorption refrigeration plant is

1. 1. 100 tons

   2. 1000 tons

   3. 7000 tons

   4. None

ANS: (c)

    17. With decrease of evaporator temperature, cooling capacity of a system

1. 1. Increases

   2. Decreases

   3. Remains same

   4. None

ANS: (b)

    18.  With decrease of evaporator temperature in a vapor absorption system, the cooling capacity remains same by controlling the

1. 1.  Expansion valve

   2.  Heating in the generator

   3.  Cooling in the condenser

   4. None

ANS: (b)

    19. Electric power requirements in vapor absorption system vs vapor compression system with same cooling

1. 1. Increase

   2. Decrease

   3. No change

   4. None

ANS: (b)

    20. Space requirements in vapor absorption  vs vapor compression system h

1. 1. Large

   2. Small

   3. Can’t say

   4. None

ANS: (b)

    21. Water-Lithium bromide vapor absorption system  achieves temperature of

1. 1. -15⁰C

   2. -5⁰C

   3. 0⁰C

   4. None

ANS: (d)

    22. In vapor absorption refrigeration system, compressor of vapor compression system  replaces

1. 1. Generator & a Absorber

   2. Absorber, heat exchanger, generator , analyzer and a rectifier

   3. Generator, absorber, and a rectifier

   4. None

2.  ANS: (b)

   23. The name of the vapor absorption unit using three fluids is

   1. Ammonia-water system

   2. Water- lithium bromide system

   3. Electrolux system

   4. None

ANS: (c)

    24. The three fluids used in the Electrolux refrigerator are

1. 1. Ammonia, air and water

   2. Water , air and hydrogen

   3.  Hydrogen, water and ammonia

   4. None

ANS: (c)

    25. Pressures in the condenser and evaporator of an Electrolux system are

1. 1. Different

   2. Same

   3. Can’t say

   4. None

ANS: (b)

    26. Vapor absorption system uses

1. 1. High grade energy

   2. Low grade energy

   3. Can’t say

   4. None

ANS: (b)

    27. Vapor absorption systems creates

1. 1. Ozone depletion

   2. Global warming

   3. Both (a) & (b)

   4. None

ANS: (d)

    28. The difference between the boiling points of refrigerant and absorbent should be

1. 1. <100⁰C

   2. >100⁰C

   3. > 200⁰C

   4. None

ANS: (c)

    29. The absorption of refrigerant in absorbent should have

1. 1. Negative deviation from Raoult’s law

   2. Positive deviation from Raoult’s law

   3. No deviation from Raoult’s law

   4. None

ANS: (a)

    30. The refrigerant-absorbent mixture should have

1. 1. High thermal conductivity and viscosity

   2. High viscosity & low thermal conductivity

   3. Low viscosity & high thermal conductivity

   4. None

ANS: (c)

    31. Absorption of refrigerant in absorbent results in the

1. 1. Absorption of heat

   2. Release of heat

   3. No absorption or release of heat

   4. None

ANS: (b)

    32. The vapor absorption system gives

1. 1. Continuous refrigeration

   2. Intermittent refrigeration

   3. Can’t say

   4. None

ANS: (a)

    33. The ammonia water system and water lithium bromide vapor absorption system have

1. 1. 1 expansion valve

   2. 2 expansion valves

   3. 4 expansion valves

   4. None

ANS: (b)

    34. The mixing of refrigerant and absorbent should be

1. 1. Endothermic

   2. Exothermic

   3. Can’t say

   4. None

ANS: (a)

    35. Vapor absorption refrigeration system uses

1. 1. Synthetic refrigerants

   2. Natural refrigerants

   3. Can’t say

   4. None

ANS: (b)

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