RAC: Important MCQs | set 1 - Mechanicaltalks - Mechanicaltalks

RAC: Important MCQs | set 1 – Mechanicaltalks

Here are top 20 important MCQs of REFRIGERATION. Read the questions carefully and try to answer all of them from your own.

Q1. A good refrigerant should have

(a) high latent heat of vaporisation and low freezing point

(b) high operating pressures and low freezing point

(c) high specific volume and high latent heat of vaporisation

(d) low C.O.P. and low freezing point.

Q2. The undesireable property of a refrigerant is

(a) non-toxic

(b) non-explosive

(c) non-flammable

(d) high boiling point

Q3. The freon group of refrigerants are

(a) halo-carbon refrigerants

(c) inorganic refrigerants

(b) azeotrope refrigerants

(d) hydro-carbon refrigerants

Q4. Which of the following refrigerant has the lowest freezing point?

(a) R-11

(b) R-12

(c) R-22

(d) Ammonia

Q5. R-11 has the highest critical point temperature.

(a) Correct

(b) Incorrect

Q6. A refrigerant with the highest critical pressure is

(a) R-11

(b) R-12

(c) R-22

(d) Ammonia

Q7. The material of pipe lines for a system using freon as a refrigerant should be

(a) brass

(b) copper

(c) steel

(d) aluminium

Q8. The material of pipe lines for a system using ammonia as a refrigerant should be copper.

(a) Yes

(b) No

Q9. The leakage in a refrigeration system using freon is detected by

(a) halide torch

(b) sulphur sticks

(c) soap and water

(d) all of these

Q10. The colour of the flame of halide torch, in case of leakage of freon refrigerant, will change –

(a) orange

(b) bright green

(c) yellow

(d) red

Q11. The leakage in a refrigeration system using ammonia is detected by

(a) halide torch

(b) sulphur sticks

(c) soap and water

(d) all of these

Q12. Which of the following statement is correct for ammonia as a refrigerant?

(a) It is toxic to mucous membranes.

(b) it requires large displacement per TR compared to fluorocarbons

(c) It reacts with copper and its alloys

(d) all of these

Q13. The sulphur sticks, in case of leakage of ammonia refrigerant, gives white smoke.

(a) True

(b) False

Q14. The boiling point of ammonia is

(a) – 10.5°C

(b) -30°C

(c) -77.7° C.

(d) -33.3°C

Q15. The boiling point of carbon dioxide is

(a) -20.5°C

(b) -50°C

(c) -63.3°C

(d) -78.3°C

Q16. The refrigerant widely used in domestic refrigerators is

(a) sulphur dioxide

(b) ammonia

(c) carbon dioxide

(d) R -12

Q17. In absorption vapour systems, the refrigerant widely used is R-12.

(a) Right

(b) Wrong

Q18. In larger industrial and commercial reciprocating compression systems, refrigerent widely used is

(a) ammonia

(b) carbon dioxide

(c) sulphur dioxide

(d) R-12

Q19. The freezing point of sulphur dioxide is

(a) -56.6°C

(b) -75.2°C

(c) -77.7°C

(d) -137.8°C

Q20. The freezing point of R-12 is

(a) -86.6°C

(b) -98.2°C

(c) -107.7°C

(d) -135.8°C

That was the set 1 of top important MCQs of  REFRIGERATION. This will help a lot for the competitive examinations. If you like this content then do share this with your well wishers. If you have any doubts regarding any mechanical engineering then let us know in comment section or contact us through email.

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