MCQ in Refrigeration Engineering Part 1 | ME Board Exam

(Last Updated On: December 26, 2020)

This is the Multiple Choice Questions Part 1 of the Series in Refrigeration Engineering as one of the Mechanical Engineering topic. In Preparation for the ME Board Exam make sure to expose yourself and familiarize in each and every questions compiled here taken from various sources including but not limited to past Board Exam Questions in Mechanical Engineering field, Mechanical Engineering Books, Journals and other ME References. I assume you are looking for a reviewer that will help you achieve your goal to become a License Mechanical Engineer very soon. Yes, you are in the right place to make your dream come true. Make sure to familiarize each and every questions to increase the chance of passing the Mechanical Board Examination.

MCQ Topic Outline included in ME Board Exam Syllabi

• MCQ in Principles of Different Refrigeration Systems
• MCQ in Determination of Cooling Loads
• MCQ in Basic Design of Ice Plants, Cold Storage and Skating Rinks
• MCQ in Instrumentation and Controls

Start Practice Exam Test Questions Part 1 of the Series

Choose the letter of the best answer in each questions.

1. Which of the following could be used to check a leak in an ammonia system?

A. Litmus paper

B. Halide torch

C. Sulfur stick

D. A and C

2. Ammonia leaks in the condenser can be detected by:

A. smelling the discharge water

B. applying litmus paper to the circulating water discharge

C. adding oil of peppermint to the system and tracing and looking for bubbles

D. applying a soapy solution to the condenser heads and looking for bubbles

3. A sulfur stick burning in the presence of ammonia will give off a _______.

A. dense yellow smoke

B. dense yellow smoke

C. dense white smoke

D. dense green smoke

4. An ammonia leak will turn litmus paper __________.

A. blue

B. green

C. red

D. yellow

5. In an ammonia system the oil gauge must be kept:

A. closed except when checking oil level

B. open at all times

C. close when machine is shut down

D. open when machine is shut down

6. Valves and piping in an ammonia system are made of:

A. brass

B. bronze

C. iron

D. copper

7. The relief valve on an ammonia machine is located :

A. on the discharge pipe from the condenser

B. on the discharge pipe from the compressor

C. in the compressor head

D. A and B

8. When purging an ammonia condenser into a bucket of water, one can tell when the air is out and ammonia starts to come through by the

A. smell of the ammonia being liberated from the water

B. color of the water turning green

C. color of the water turning bluish

D. change of bubbling sound of air to the crackling sound of ammonia

9. The crossover connection in an ammonia system can be used to ______.

A. hot-gas defrost

B. pump air out of the system

C. add refrigerant to the system

D. reduce the pressure on the discharge side of the condenser

10. How is an ammonia system purged so that operator will not be overcome by the fumes?

A. into a bucket of lube oil

B. back into the compressor

C. into a bucket of water

D. into the atmospheric line

11. Thermal expansion valves are usually of the :

A. diaphragm

B. magnetic type

C. bellows type

D. A and C

12. When checking zinc plates in a condenser, one should :

A. install all new plates

B. clean the plates and renew worn out ones

C. ground each plate to the shell

D. paint the plates with red lead

13. The scale trap is located between the :

A. compressor and oil separator

B. expansion valve and evaporators coils

C. King (liquid) valve and expansion valve

D. evaporator coils and compressor

14. When the evaporator coils are located in the icebox, the system is known as :

A. indirect system

B. direct system

C. high-pressure system

D. low-pressure system

15. The purge valve is located :

A. on the receiver discharge

B. in the highest part of the system

C. in the lowest part of the system

D. on the evaporators coils

16. The solenoid valve is :

A. a pressure-controlled stop valve

B. a temperature-controlled stop valve

C. a Freon-controlled check valve

D. none of these

17. The thermal expansion valve is located between the :

A. solenoid valve and the evaporator coils

B. charging valve and the solenoid valve

C. receiver and the king valve

D. king valve and the solenoid valve

18. The purpose of the scale trap is to :

A. dissolved scale and dirt in the system

B. remove insoluble gases from the refrigerant

C. remove dirt, scale and metal chips from the refrigerant

D. control the amount of scale going to the compressor

19. The oil separator (trap) is located between the :

A. compressor discharge valve and the condenser

B. receiver and the expansion valve

C. receiver and the king valve

D. condenser and the receiver

20. The charging connection in a refrigerating system is located

A. before the receiver

B. between the condenser and the receiver

C. between the receiver and the king valve

D. between the king valve and the solenoid valve

21. The dehydrator is located

A. condenser and receiver

B. receiver and the expansion valve

C. condenser and the king valve

D. receiver and the king valve

22. The charging valve is located between the :

A. king valve and the expansion valve

B. evaporator coils and the compressor

C. compressor and the receiver

D. receiver and the condenser

23. The solenoid valve is located between the ______

A. thermal expansion valve and the evaporator

B. scale trap and the thermal expansion valve

C. king valve and the scale trap

D. automatic and manual expansion valves

24. A device used to keep moisture from passing through the system is called :

A. humidifier

B. dehydrator

C. aerator

D. trap

25. The relief valve is located on the :

A. discharge side on the condenser

B. outlet of the evaporator coils

C. receiver tank

D. discharge side of the compressor

26. The dehydrator is used :

A. to remove moisture from the system

B. when adding refrigerant to the system

C. to remove air from the system

D. A and B

27. Which of the following is another name for the liquid valve ?

A. Freon valve

B. king valve

C. shutoff valve

D. master valve

28. If no gaskets are used in the piping joints of a Freon system, the

A. wielded joints

B. finished joints

C. ground joints

D. soldered joints

29. A device for holding open the suction valve and drawing gas from the suction manifold and returning it to the suction line without compressing is called _______.

A. relief valve

B. suction by-pass

C. cylinder unloader

D. discharge line by-pass

30. The solenoid valve can be typed as a ________.

A. bellow valve

B. bimetallic valve

C. thermal valve

D. magnetic stop valve

31. The bulb for the thermal expansion valve is located

A. near the evaporator coil outlet

B. in the middle of evaporator coils

C. near the evaporator coil inlet

D. on the bottom row of evaporator coils

32. The elements of a thermostat switch are usually of the ______.

A. pilot-valve type

B. bimetal type

C. diaphragm type

D. valve type

33. The expansion valve is located between the

A. compressor and condenser

B. evaporator and compressor

C. receiver and evaporator

D. condenser and receiver

34. The oil separator is located between the

A. condenser and dehydrator

B. compressor and condenser

C. evaporator and compressor

D. solenoid valve and thermal expansion valve

35. Zinc rods are found in the

A. salt-water side of condenser

B. compressor crankcase

C. prevent gas from getting to crankcase

D. all of these

36. A double-trunk piston is used to

A. prevent oil from mixing with the refrigerant

B. absorb some of the side thrust

C. prevent gas from getting to crankcase

D. all of these

37. Which of the following gasket materials should be used on a Freon system?

A. Asbestos

B. Metallic

C. Rubber

D. A and B

38. Many pressure gauges on a Freon system have two dials or graduations on one gauge. The two dials represent

A. suction and discharge pressure

B. pressure and temperature

C. liquid and gas pressure

D. cooling water inlet and outlet temperatures

39. A double-pipe condenser has __________

A. two pipes for cooling water and one for refrigerant

B. a small pipe inside a larger pipe, the cooling water passing through the small pipe and the refrigerant through the large pipe

C. two piping system side by side, one with cooling water and one with refrigerant

D. none of these

40. When there is a Freon leak, the torch will burn :

A. orange

B. green

C. blue

D. white

41. Large leaks in a Freon system cannot always be detected with a halide torch because it changes color with the slightest amount of Freon present. A large leak can be detected easier by applying ________

A. sheets of litmus paper to all joints and watch for color change

B. a soapsuds solution, mixed with a little glycerin to hold the solution together, and watch for bubbles

C. a thin layer of mineral oil to all joints and watch for bubbles

D. a lighted candle at the joints and watch for leaky spots blowing candle

42. The relief valve on a CO₂ Machine is located

A. next to the king valve

B. in the compressor head

C. on the discharge pipe between the compressor and the discharge valve

D. on the discharge pipe from the condenser

43. The discharge pressure of the compressor should be:

A. the pressure which corresponds to a temperature from 5°F below that of the condenser discharge

B. the pressure which corresponds to a temperature equal to that of the condenser discharge

C. the pressure which corresponds to a temperature from 5°F to 15°F higher than the condenser discharge

D. none of these

44. The purpose of relief valves on refrigeration machines is to:

A. by-pass the compressor when dehydrating

B. prevent overloading in the iceboxes

C. prevent excessive pressure in case of stoppage on the discharge side of the system

D. A and B

45. A leaky suction valve can usually be detected by

A. a higher suction pressure

B. a fluctuating suction pressure gauge

C. closing in on the suction valve having no effect on the suction pressure

D. any of these

46. Too low suction pressure could be caused by

A. too much oil in the system

B. shortage of refrigerant gas

C. dirty scale traps

D. any of these

47. What do you call a system in which the evaporator coils are located in a brine solution and the brine is pumped through the inbox?

A. an indirect system

B. a double-evaporator system

C. a direct system

D. a low-pressure system

48. Before securing a compressor to do maintenance work on it, be sure to

A. purge the system

B. have spare parts ready

C. pump down the system

D. B and C

49. Obstruction of the valve is usually caused by

A. scale

B. congealed oil the system

C. water in the system

D. any of the answer

50. Excess frost on the evaporator coils

A. does not affect the system

B. takes load off compressor

C. reduces efficiency of the plant

D. keeps the icebox cooler