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5th Class Power Engineering Book 2 > FINAL - Book 2 Review > Flashcards

FINAL - Book 2 Review Flashcards

1
Q 
1.	The chilled water temperature switch will shut down the compressor if the temperature of the water leaving the chiller drops to approximately:
A.	0°C – 0.5°C (32°F - 33°F)
B.	1°C – 1.5°C (34°F - 35°F)
C.	2.5°C - 3°C (36.5°F – 37.5°F)
D.	1.5°C - 2°C (35°F – 35.5°F)
E.	2°C – 2.5°C (35.5°F – 36.5°F)
A

C. 2.5°C - 3°C (36.5°F – 37.5°F)

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2
Q 
2.	What brine temperature is used when cooling an ice surface?
A.	-11°C (12°F)
B.	-5°C (23°F)
C.	-18°C (0°F)
D.	-25°C (-13°F)
E.	-50°C (-58°F)
A

A. -11°C (12°F)

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3
Q 
3.	What size packing should be used if the stuffing box bore on a pump is 63.5 mm (2.5 in.) and the shaft diameter is 50.8 mm (2 in.)?
A.	12.7 mm (1/2 in)
B.	19.05 mm (3/4 in)
C.	9.525 mm (3/8 in)
D.	6.35 mm (1/4 in)
E.	4.76 mm (3/16 in)
A

D. 6.35 mm (1/4 in)

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4
Q 
4.	The float rod should be adjusted so that it will close the inlet valve and shut off the water about \_\_\_\_\_ from the top of the overflow pipe.
A.	6.4 mm (1/4 in)
B.	12.7 mm (1/2 in)
C.	25.4 mm (1 in)
D.	19.1 mm (3/4 in)
E.	31.7 mm (1 1/4 in)
A

C. 25.4 mm (1 in)

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5
Q 
5.	Electrical control systems usually employ a normal line voltage of:
A.	120 or 240 volts AC
B.	120 or 240 volts DC
C.	12 or 24 volts AC
D.	12 or 24 volts DC
E.	240 or 600 volts AC
A

A. 120 or 240 volts AC

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6
Q 
6.	The sliding vane compressor may have a discharge pressure as high as:
A.	3000 kPa (435 psi)
B.	1000 kPa (145 psi)
C.	5000 kPa (725 psi)
D.	2000 kPa (290 psi)
E.	4000 kPa (580 psi)
A

B. 1000 kPa (145 psi)

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7
Q 
7.	A single-stage centrifugal compressor is one with a single impeller and may be able to compress atmospheric air to a pressure of about:
A.	500 kPa (72.5 psi)
B.	200 kPa (29 psi)
C.	100 kPa (14.5 psi)
D.	300 kPa (43.5 psi)
E.	600 kPa (87 psi)
A

D. 300 kPa (43.5 psi)

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8
Q 
8.	The circulator in smaller systems normally produces only a slight pressure differential and, even when it is placed in the return line, a pressure of \_\_\_\_\_ will ensure that sufficient positive pressure is maintained at the highest points in the system.
A.	25 kPa (4 psi)
B.	83 kPa (12 psi)
C.	55 kPa (8 psi)
D.	10 kPa (1.5 psi)
E.	100 kPa (15 psi)
A

B. 83 kPa (12 psi)

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9
Q 
9.	Steam in a two-pipe, vacuum return system is supplied pressures up to:
A.	75 kPa (10 psi)
B.	50 kPa (7 psi)
C.	200 kPa (30 psi)
D.	103 kPa (15 psi)
E.	15 kPa (2 psi)
A

D. 103 kPa (15 psi)

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10
Q
  1. The water pressure in most a hot water heating system is in between:
    A. 85 kPa to 140 kPa (12.3 psi to 20.3 psi)
    B. 75 kPa to 110 kPa (10.9 psi to 16 psi)
    C. 250 kPa to 300 kPa (36.3 psi to 43.5 psi)
    D. 100 kPa to 150 kPa (14.5 psi to 21.8 psi)
    E. 70 kPa to 94 kPa (10.2 psi to 13.6 psi)
A

A. 85 kPa to 140 kPa (12.3 psi to 20.3 psi)

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11
Q 
11.	Ordinarily, the most economical group relamping period is about \_\_\_\_\_ of rated life of the lamp.
A.	100%
B.	60%
C.	90%
D.	50%
E.	70%
A

E. 70%

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12
Q 
12.	The CSA B52 Mechanical Refrigeration Code requires that the pressure limiting device be designed to stop the action of the compressor or generator at a pressure not more than \_\_\_\_\_ of the system high side design pressure.
A.	80%
B.	100%
C.	70%
D.	90%
E.	60%
A

D. 90%

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13
Q 
13.	The closed expansion tank in hot water heating system has a gauge glass showing the level of water and air in the tank and would normally be from \_\_\_\_\_ the capacity of the tank.
A.	1/8 to 1/3
B.	1/4 to 1/2
C.	1/2 to 2/3
D.	1/2 to 3/4
E.	3/4 to 7/8
A

. C. 1/2 to 2/3

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14
Q 
14.	The Hartford loop prevents steam pressure from forcing boiler water back into the return line should the:
A.	Boiler pressure get to high
B.	Feedwater supply fail
C.	Check valve fail to close
D.	Water level get to high
E.	Boiler temperature be to high
A

C. Check valve fail to close

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15
Q
  1. Which of the following statements about centrifugal pumps is false?
    A. Never run the pump in a dry condition even for a few minutes
    B. Vent any air present from the seal housing before start up
    C. Make sure an adequate flow of cooling liquid is flowing to the seal
    D. Start the pump with the inlet valve closed
    E. Start the pump with the discharge valve closed
A

D. Start the pump with the inlet valve closed

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16
Q 
16.	Possible causes of a centrifugal pump discharge pressure being too low may include all of the following except:
A.	Speed too low
B.	Worn wearing rings
C.	Damaged impeller
D.	Worn packing
E.	Impeller diameter too large
A

E. Impeller diameter too large

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17
Q
  1. The rotary screw compressor features two intermeshing rotors contained within a close-fitting casing the:
    A. Male rotor is usually the driven one
    B. Female rotor has six concave flutes
    C. Rotors do not come in contact with each other so internal lubrication is not required.
    D. Male rotor has four concave lobes
    E. Female rotor is driven by means of timing gears
A

D. Male rotor has four concave lobes

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18
Q
  1. A heat exchanger is used in a compression refrigerating system to transfer heat to the:
    A. Cold vapour being drawn from the evaporator
    B. Hot vapour being drawn from the evaporator
    C. Cold vapour being drawn from the condenser
    D. Hot vapour being drawn from the condenser
    E. Cold liquid being drawn from the evaporator
A

A. Cold vapour being drawn “from the evaporator”

Note: From the Evaporator

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19
Q 
19.	In a typical electric control system the electric current is transmitted through a wire called the \_\_\_\_\_ to the burner.
A.	Neutral line
B.	Positive loop
C.	Negative loop
D.	Control link
E.	Connecting link
A

E. Connecting link

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20
Q
  1. A pump is a mechanism that is used to _____ by imparting energy to the liquid being transferred.
    A. Transfer a fluid from one place to another
    B. Develop a static suction pressure
    C. Raise a fluid from a lower level to a higher level
    D. Create a pressure differential only
    E. Raise a fluid from a higher level to a lower level
A

A. Transfer a fluid from one place to another

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21
Q
  1. Mechanical seals have all the following advantages over packing except that they:
    A. Are less expensive than packing
    B. Requires less maintenance
    C. Do not produce wear on shafts
    D. Reduce leakage to a minimum
    E. Can work under very high temperatures and pressures
A

A. Are less expensive than packing

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22
Q 
22.	One of the methods employed to prevent backflow and control the cross connections is the:
A.	Air globe
B.	Reduced temperature principal device
C.	Double check breaker
D.	Temperature vacuum breaker
E.	Atmospheric vacuum breaker
A

E. Atmospheric vacuum breaker

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23
Q
  1. Which of the following should not be included in the routine operation of a hot water heating system?
    A. Test the safety relief valve on a regular basis
    B. Keeping the boiler room and boiler clean and tidy
    C. Keep covers on all controls
    D. Make sure that the air supply to the boiler room is closed
    E. Test the controls on a regular basis
A

D. Make sure that the air supply to the boiler room is closed

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24
Q 
24.	Heat passes through building walls, ceilings, and floors from the warmer inner surfaces to the cooler outer surfaces by:
A.	Construction
B.	Conservation
C.	Occupation
D.	Insulation
E.	Conduction
A

E. Conduction

25
Q 
25.	If the bearing can be easily replaced, such as in a car engine, it is termed a \_\_\_\_\_ type.
A.	Ball
B.	Roller
C.	Sleeve
D.	Journal
E.	Shell
A

E. Shell

26
Q 
26.	The category of air conditioning system that provides air filtration, heating, cooling, and/or humidification in an air handling unit located in a central mechanical room in the building is the \_\_\_\_\_ system.
A.	Dual Duct
B.	Unitary
C.	Combined
D.	Central
E.	Terminal reheat
A

D. Central

27
Q 
27.	Unit ventilators are often equipped with three-speed switches used to regulate the:
A.	Position of the damper
B.	Flow of the steam
C.	Flow of the water
D.	Speed of the fan
E.	Rate of ventilation
A

D. Speed of the fan

28
Q 
28.	A disadvantage of the \_\_\_\_\_ method of capacity control is that the power required by the compressor does not change even though the amount of system cooling effect is reduced.
A.	Cylinder bypass
B.	Intermittent operation
C.	Speed control
D.	Hot gas bypass
E.	Compressor unloader
A

D. Hot gas bypass

29
Q 
29.	One of the ways that heat is transmitted is by:
A.	Construction
B.	Occupation
C.	Insulation
D.	Convection
E.	Conservation
A

D. Convection

30
Q 
30.	Trouble may result from the presence of non-condensable gases in the compression refrigeration system:
A.	Evaporator
B.	Compressor
C.	Condenser
D.	Absorber
E.	Regenerator
A

C. Condenser

31
Q 
31.	Which one of the following factors affect the leakage tendency of a refrigerant?
A.	Enthalpy
B.	Miscibility
C.	Temperature
D.	Specific volume
E.	Density
A

E. Density

32
Q 
32.	Where the materials of moving surfaces are in contact with each other, they tend to cling or weld together resulting in extra force called the \_\_\_\_\_ force being required to move the surfaces.
A.	Reaction
B.	Friction
C.	Normal
D.	Gravitational
E.	Centrifugal
A

B. Friction

33
Q 
33.	A fin coil consists of one or more rows of parallel tubes fitted with fins to \_\_\_\_\_ exchange.
A.	Decrease the rate of heat
B.	Increase the rate of heat
C.	Increase the temperature
D.	Decrease the temperature
E.	Increase the flow rate
A

B. Increase the rate of heat

34
Q 
34.	If the refrigeration compressor is equipped with an oil sump heater, ensure it is energized and that the oil temperature is high enough to drive off any:
A.	Air
B.	Carbon dioxide
C.	Refrigerant
D.	Oil
E.	Water
A

C. Refrigerant

35
Q 
35.	The viscous impingement filter contains filter media of tightly packed glass fibre, copper or aluminum wool, crimped metal, etc., that is coated with a \_\_\_\_\_ fluid.
A.	Oily
B.	Glue like
C.	Vegetable oil
D.	Petroleum oil
E.	Viscous or sticky
A

E. Viscous or sticky

36
Q 
36.	Fixed oils also called fatty oils produced from all of the following except:
A.	Lard
B.	Whale oil
C.	Castor oil
D.	Petroleum oil
E.	Cottonseed oil
A

D. Petroleum oil

37
Q 
37.	The humidification process refers to adding \_\_\_\_\_ to the air.
A.	Water vapour or moisture
B.	Heat
C.	Temperature
D.	Enthalpy
E.	Steam
A

A. Water vapour or moisture

38
Q 
38.	One of the causes of insufficient steam supply to the heating units can be attributed to:
A.	Proper pitch unrestricted drainage
B.	Air vents passing air
C.	Valves on mains partly closed
D.	Piping over sized restricting flow
E.	Bypassing of steam to supply line
A

C. Valves on mains partly closed

39
Q 
39.	In modern installations the cast-iron radiator has largely been replaced by the:
A.	Ventilator
B.	Convector
C.	Unit heater
D.	Space heater
E.	Hot air furnace
A

B. Convector

40
Q
  1. bearing failure due to:
    A. Hard pieces of lubricant being pressed into the bearing surfaces producing flaking and pitting
    B. The force applied indenting or nicking the balls or rollers
    C. Uneven loading of the bearing
    D. High operating temperatures
    E. Cracking of the rollers
A

B. The force applied indenting or nicking the balls or rollers

41
Q 
41.	In the \_\_\_\_\_ system the maximum building demand for water is less than the maximum flow available from a municipal or local distribution system.
A.	Pressure with pneumatic tank
B.	Tank variable pressure
C.	Indirect constant pressure
D.	Direct pressure
E.	Tankless constant pressure
A

E. Tankless constant pressure

42
Q 
42.	The vane closed switch is in the motor starting circuit so that the compressor can only be started when the vanes are in the \_\_\_\_\_ position.
A.	Evaporator open
B.	Compressor closed
C.	Compressor open
D.	Evaporator closed
E.	Closed position
A

E. Closed position

43
Q 
43.	Radiators may be classified as \_\_\_\_\_ type.
A.	Horizontal
B.	Flooded
C.	Vertical
D.	Airless
E.	Window
A

E. Window

44
Q
  1. Backflow in a potable water supply is the _____ of water or other liquid, gas, mixture, or other substance into the distributing pipes.
    A. Change in pressure
    B. Reversal of the direction of the normal flow
    C. Change of temperature
    D. Reversal of pressure
    E. Reversal of temperature
A

B. Reversal of the direction of the normal flow

45
Q 
45.	The operation of the compressor (starting, stopping, and unloading) may be accomplished by a \_\_\_\_\_ type of actuated control.
A.	Humidity
B.	Volume
C.	Mass
D.	Density
E.	Level
A

A. Humidity

46
Q
  1. Moisture in the refrigerant may lead to:
    A. Ice forming in the condenser
    B. Over cooling of the refrigerant
    C. High pressure in the evaporator
    D. Low temperature in the condenser
    E. Ice formation between the valve and valve seat of the regulating or expansion valve
A

E. Ice formation between the valve and valve seat of the regulating or expansion valve

47
Q 
47.	The refrigeration condenser must remove \_\_\_\_\_ absorbed in the evaporator, along with the heat of compression added to the refrigerant by the compressor.
A.	Both the latent and sensible heat
B.	The latent heat
C.	The sensible heat
D.	The enthalpy and entropy
E.	Both the temperature and pressure
A

A. Both the latent and sensible heat

48
Q 
48.	Which one of the following factors affect the leakage tendency of a refrigerant?
A.	Temperature
B.	Viscosity
C.	Enthalpy
D.	Specific volume
E.	Miscibility
A

B. Viscosity

49
Q 
49.	In a \_\_\_\_\_ system, the mains are located above the heating units.
A.	Steam supply
B.	Heating supply
C.	Upfeed
D.	Downfeed
E.	Under floor
A

D. Downfeed

50
Q
  1. When the pump is located above the source of supply and the priming water is supplied from the pump discharge line the pump is primed in the following manner except:
    A. Open the discharge valve
    B. Open the priming valve
    C. Open the air vent valve
    D. Water flows into the pump and suction line where it is prevented from escaping by the foot valve
    E. When water flows from the vents the pump is primed
A

A. Open the discharge valve

51
Q 
51.	The presence of air in a steam heating system is undesirable since it will:
A.	Decrease the condensate pressure
B.	Promote corrosion in the system
C.	Increase heat transfer beyond design
D.	Increase the steam flow
E.	Contaminate the makeup water
A

B. Promote corrosion in the system

52
Q 
52.	Frequently, it is possible to improve the desirable characteristics of lubricating oil by the use of all of the following additives except:
A.	Anti-oxidants
B.	Detergent-dispersants
C.	Pour point depressants
D.	Emulsion breakers
E.	Corrosion inhibitors
A

D. Emulsion breakers

53
Q 
53.	The condenser high pressure cutout is a high limit switch that is generally activated by:
A.	High evaporator temperature
B.	Inadequate condenser cooling
C.	Low condenser pressure
D.	High compressor discharge temperature
E.	An overloaded evaporator
A

B. Inadequate condenser cooling

54
Q 
54.	Living organisms that must be removed from the air are:
A.	Insects and pollen
B.	Bacteria and spores
C.	Bacteria and insects
D.	Pollen and spores
E.	Bacteria and pollen
A

B. Bacteria and spores

55
Q 
55.	A refrigeration system using a high-pressure float provides for storage of the refrigerant in the:
A.	Evaporator
B.	Compressor
C.	Condenser
D.	Expansion valve
E.	Receiver
A

A. Evaporator

56
Q 
56.	The high pressure in the condenser is maintained by the:
A.	Compressor
B.	Expansion valve
C.	Evaporator
D.	Receiver
E.	Chiller
A

A. Compressor

57
Q 
57.	Wastes from plumbing fixtures, such as sinks, are discharged through the fixture outlet pipe and P-trap then passes into a:
A.	Horizontal Line
B.	Vertical stack
C.	Vertical branch
D.	Horizontal branch
E.	Horizontal stack
A

D. Horizontal branch

58
Q 
58.	Electrical contacts that complete electric circuits when a relay is de-energized are referred to as \_\_\_\_\_ contacts.
A.	Naturally open (NO)
B.	Normally open (NO)
C.	Normally closed (NC)
D.	Naturally Closed (NC)
E.	Not open (NO)
A

C. Normally closed (NC)

59
Q
  1. What precaution must be provided when using ultraviolet lighting for sterilizing air in ventilation systems?
    A. Correct supply voltage
    B. Safety glasses
    C. Sufficient number of units
    D. Positioning the lamps so the rays cannot hit occupants
    E. Used only in unoccupied areas
A

D. Positioning the lamps so the rays cannot hit occupants

5th Class Power Engineering Book 2 (34 decks)

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