Self Test Flashcards
Magnetite is also known as: A) iron ore B) non ferrous metal C) lodestone D) hematite E) limonite
C) lodestone
An anti-friction bearing: A) is constructed with white metal alloy B) eliminates all bearing friction C) wears to a smooth, low-friction surface D) has rolling friction E) is a sleeve bearing
D) has rolling friction
One function of vibration absorbers is to:
A) lower noise levels
B) allow the load on the system to increase dramatically without straining the components in the system
C) increase longevity of the system
D) insulate piping and make the system more efficient
E) align piping
A) lower noise levels
A screwdriver having a square tip is known as: A) a slot B) an Allen C) a Robertson D) a Phillips E) a Jacobson
C) a Robertson
The equivalent resistance of three resistances of 10, 25, and 50 ohms in parallel is \_\_\_\_\_ ohms. A) 0.16 B) 6.25 C) 85 D) 18.75 E) 8.5
B) 6.25
One of the disadvantages of the gravity hot water system is:
A) the water temperature must be very high to compensate for the heat losses
B) piping used must be rated for high temperature services
C) there is a slow response to changes in heat demand
D) the maximum water temperature is limited to approximately 100*C
E) high maintenance
C) there is a slow response to changes in heat demand
The capacity of a centrifugal pump:
A) varies with discharge pressure
B) is fixed and can only be altered by changing the impeller
C) indicates that the unit is a positive displacement type
D) should be varied by suction valve manipulation
E) can be altered by speed variation only
A) varies with discharge pressure
Temperature relief devices limit the temperature in domestic hot wate systems to no more than: A) 50*C B) 79*C C) 90*C D) 99*C E) 121*C
D) 99*C
In nearly all LP steam heating systems, the feedwater:
A) is condensate
B) requires daily close scrutiny of chemical values
C) contains a high percentage of makeup water
D) is deaerated
E) is softened
A) is condensate
Large power production plants tend to be of the thermal type because they can burn solid fuels and:
A) they are the least expensive to build
B) the noise level is much less than internal combustion engines
C) the heat cycle they use is the most efficient
D) solid fuels are the most plentiful and the cheapest
E) they require the least amount of manpower
C) the heat cycle they use is the most efficient
The control used in mechanical refrigeration systems to maintain a constant level of liquid refrigerant in the accumulator tank of a flooded evaporator is called: A) a thermostatic expansion valve B) an automatic expansion valve C) a low-pressure float valve D) a hand operated expansion valve E) a high-pressure float valve
C) a low-pressure float valve
If possible, you should not work any higher than \_\_\_ steps from the top of a ladder. A) three B) two C) one D) four E) five
A) three
Intercoolers:
A) must have a drain
B) are more efficient when cooled with air than with water
C) are used on double acting single stage compressors
D) help increase the volume of the air
E) should use an antifreeze solution
A) must have a drain
Fibrous glass blankets, when attached to the insides of air ducts, primarily:
A) restrict the spread of smoke
B) insulate the ductwork
C) act as a fire retardant
D) attenuate transmitted mechanical noise
E) stop air leakage in the seams of the ductwork
D) attenuate transmitted mechanical noise
When using a hammer to lightly strike a tube of a hot oil heater, a ringing sound likely indicates that the tube: A) is free of deposits B) has hard coke deposits C) is empty D) has a crack in it E) is full
A) is free of deposits
A transformer is a device that is used to change: A) AC amperage to DC amperage B) AC voltage from one value to another C) DC amperage from one value to another D) DC voltage to AC voltage E) low power to high power
B) AC voltage from one value to another
When using mechanical fuel oil atomization:
A) a 70 kPa steam pressure is required at the burner
B) dry saturated steam or superheated steam should be used
C) high pump pressure is required
D) steam pressure is required to keep the bypass open
E) 35 to 40 kPa oil pressure is required
C) high pump pressure is required
Transformers are rated in: A) polarity B) service factor C) watts D) core temperature E) kVA
E) kVA
Which of the following is a programming language? A) English B) Word C) Desktop publishing D) Latin E) Pascal
E) Pascal
A flowing liquid has kinetic energy as a function of its velocity. When it’s velocity increases:
A) potential energy in the form of pressure will also increase
B) the cross-sectional area of the piping must increase
C) the mass quantity flowing per second will decrease
D) potential energy in the form of pressure will decrease
E) density will decrease
D) potential energy in the form of pressure will decrease
A high flash point in oil reduces the risk of: A) pump cavitation B) condensation C) vapour bubble formation D) heat transfer E) fire
E) fire
The \_\_\_\_ of the completed job depends largely on the care taken during laying out. A) time B) accuracy C) cost D) price E) size
B) accuracy
In a meat processing plant, the sales cooler is maintained at a temperature of approximately: A) 10*C B) -0*C C) -3*C D) -11*C E) -35*C
C) -3*C
A circulating pump is usually: A) connected with some kind of heat exchanger system B) a once-through device C) a reciprocating pump D) a small capacity pump E) a high head pump
A) connected with some kind of heat exchanger system
Organic growths also called \_\_\_\_\_ can reduce the flow ratio in heat exchanger tubes and channels. A) algae B) slime C) fungi D) spores E) silt
B) slime
The major difference between AC and a DC generator is that a DC generator has: A) a rotor B) a commutator C) slip rings D) a field E) a stator
B) a commutator
A slight leakage is desired between the pump shafts and the packing in order to: A) prevent the ingress of air B) increase pump capacity and efficiency C) prevent wearing of the wear rings D) lubricate the shaft and packing E) prevent the pump from vapour licking
D) lubricate the shaft and packing
The feature of an impulse turbine that prevents a drop in pressure as the steam passes through the blades is:
A) the shape of the steam passages between adjacent blades
B) the lower shaft speed
C) the back torque on the driver
D) the higher temperature of the inlet steam
E) the momentum of the load
A) the shape of the steam passages between adjacent blades
When joining two ropes of different diameters, we use a: A) reef knot B) sheet bend C) figure eight knot D) sheep shank E) round turn and three half hitches
B) sheet bend
Finned tube coils in air handling systems are often called: A) fish coils B) bare tube coils C) extended surface coils D) cooling coils E) heating coils
C) extended surface coils
Dry-bulb temperature is:
A) the absolute temperature corresponding to the atmospheric pressure
B) the same as the wet-bulb temperature if the relative humidity is less than 100%
C) not required to find the relative humidity
D) the temperature of the air measured with an ordinary thermometer
E) the dew point temperature
D) the temperature of the air measured with an ordinary thermometer
The rotating field of an alternator is produced by applying \_\_\_\_\_ to the rotor with: A) AC power B) reactive power C) magnetic flux D) DC power E) apparent power
D) DC power
Which of the following is not a component of the low pressure side of a compression refrigeration system?
A) compressor discharge piping
B) the evaporator
C) the downstream side of the expansion valve
D) compressor inlet
E) the suction line
A) compressor discharge piping
Transformers should be inspected at least: A) quarterly B) bi-annually C) semi-annually D) once or twice a year E) every five years
D) once or twice a year
Thermal shock to boilers can be reduced by:
A) warming up boilers quickly
B) allowing the boiler to develop a thin, insulating coating of scale
C) slowly draining hot boilers
D) preventing the full flow of cold water into a warm hot water boiler
E) starting cold boilers on “automatic”
D) preventing the full flow of cold water into a warm hot water boiler
Single element feedwater control systems are very efficient in maintaining the boiler water level when:
A) the boiler has a large water capacity
B) the boiler is a fire tube boiler
C) the fluctuations in load are slow and small
D) load demands are low
E) the boiler is gas fired
C) the fluctuations in load are slow and small
An entire centrifugal compressor refrigerating system, including the auxiliary equipment, can be stopped by simply pressing a stop button, unless:
A) the system is automatically controlled
B) the system’s auxiliary equipment is not electrically interlocked
C) the system’s auxiliary equipment can be stopped simultaneously
D) the compressor can be shut down at the same time as the other equipment
E) there is a cooling demand that must be satisfied
B) the system’s auxiliary equipment is not electrically interlocked
The residential humidifier which is commonly used in the supply plenum of smaller warm air furnaces and consists of a shallow tray partially filled with water is called a: A) bypass humidifier B) wetted element humidifier C) steam grid humidifier D) pan type humidifier E) power type humidifier
D) pan type humidifier
A system used extensively in hotels and motels due to its minimal space requirement, relatively low initial cost and high degree of individual zone control is called:
A) a hydronic heat pump system
B) an induction system
C) a variable volume system with perimeter heating
D) a fan coil unit with makeup air system
E) a compartmental atomizing system
D) a fan coil unit with makeup air system
An advantage of an electronic control system is that:
A) the controllers can accept a wide variety of inputs
B) they are inexpensive to operate
C) they are inexpensive to install
D) the controllers can be used outdoors
E) it is very compact
A) the controllers can accept a wide variety of inputs
Which of the following would be the best choice for a powerhouse control room installation? A) a minicomputer B) a mainframe computer C) a microcomputer D) a netbook computer E) a laptop computer
C) a microcomputer
Slow or insufficient heat in one or more rooms in a steam heated building can be caused by a faulty: A) steam trap B) condensate tank float switch C) heater D) return trap E) boiler limit control
A) steam trap
The purpose of the “freeze-stat” temperature controller used with hot water coils is to:
A) close the outside air dampers and stop the fan if the heat source fails or the low limit temperature controller malfunctions
B) prevent coil freeze-up by increasing the hot water flow through the coil to a maximum if the outside air temperature is too low
C) increase the heat source temperature if the outside air temperature decreases
D) shut off all water flow to the coil if a freeze condition is detected
E) increase the fan output if the return air temperature is too low
A) close the outside air dampers and stop the fan if the heat source fails or the low limit temperature controller malfunctions
The hydrocarbons in natural gas may include: A) carbon dioxide B) ethane C) hydrogen sulphide D) nitrogen E) carbonic acid
B) ethane
The low water cut-off of a low pressure steam heating boiler should be tested:
A) by electrician who specializes in boiler controls
B) by lowering the water level, and ensuring the boiler shuts off before the water reaches the bottom of the visible part of the gage glass
C) several times per shift
D) for correct operation on an annual basis
E) by first shutting off the burner, to prevent boiler damage if the cut-off should fail during testing
B) by lowering the water level, and ensuring the boiler shuts off before the water reaches the bottom of the visible part of the gage glass
An HVAC system that uses a high pressure induction system utilizes \_\_\_\_\_ to provide room air circulation. A) a nozzle arrangement B) a small fan C) several fans on one shaft D) a mixing box E) differential temperature
A) a nozzle arrangement
A pressure relief device on a refrigeration system shall have sufficient capacity to prevent the pressure in the pressure vessel from rising more than \_\_\_ above the setting of the pressure relief device. A) 11% B) 15% C) 113 kPa D) 25% E) 50%
A) 11%
The provision of outside air into a building does not: A) provide "makeup" air B) replenish the oxygen supply C) dehumidify or humidify the air D) remove doors E) ventilate the building
C) dehumidify or humidify the air
The two basic varieties of mechanical atomizing oil burners ar the:
A) variable capacity and modulating burners
B) constant and variable capacity burners
C) modulating and cluster burners
D) rotary and reciprocating cup burners
E) light oil and heavy oil burners
B) constant and variable capacity burners
The performance of a heat pump system (or c.o.p.) is the ratio of: A) heat output divided by heat input B) heat input divided by energy output C) energy input divided by energy output D) energy input divided by heat output E) heat output divided by energy input
E) heat output divided by energy input
A time delay oil valve:
A) opens when the oil pump starts
B) opens 5 to 15 seconds after ignition begins
C) opens on flame failure
D) is located on the return line
E) is upstream of the pressure regulating valve
B) opens 5 to 15 seconds after ignition begins
In a lithium bromide refrigeration system, which of the following is the refrigerant? A) lithium bromide B) ammonia C) freon-22 D) water E) strong aqua
D) water
The result of a plugged impeller will be:
A) air leaks in suction line and stuffing boxes
B) wrong direction of rotation
C) loss of prime
D) an overheated stuffing box
E) no liquid being delivered
E) no liquid being delivered
Setpoint deviation is also called: A) derivative B) proportional band C) offset D) integral E) gain
C) offset
A controller is a device that primarily:
A) sends or transmits a positive rather than negative signal
B) tries to maintain a setpoint
C) records a system’s performance
D) notifies operators of errors or faults in a system
E) is a logic device capable of making decisions
B) tries to maintain a setpoint
A hot water boiler is protected from over pressure by means of: A) a temperature relief valve B) a high limit pressure control C) an expansion tank D) an overflow tank E) a safety relief valve
E) a safety relief valve
A thrust bearing which does not utilize the oil wedge principle of lubrication is the: A) michell type B) collar type C) flotation type D) kingsbury type E) vertical type
B) collar type
In order to keep some hot oil flowing backwards through a standby pump and around the discharge check valve, it is important that the \_\_\_\_\_ valve of the standby pump be left open. A) bypass B) suction C) non-return D) check E) relief
B) suction
Air conditioning ducts are classified as:
A) low pressure and medium pressure
B) low pressure, medium pressure, and high pressure
C) fire resistant and flame suppressing
D) thin, medium, and heavy gauge
E) heating and cooling
B) low pressure, medium pressure, and high pressure
When like poles of a magnet are placed together, they will: A) be attracted to each other B) bend C) generate an electromotive force D) repel each other E) remain stationary
D) repel each other
A valve body that seals on the down stroke is: A) reverse acting B) single sealed C) direct acting D) double sealed E) unidirectional
C) direct acting
The concentration of lithium bromide in an absorption refrigerating system will change while:
A) going through the expansion valve
B) going through the suction valve
C) cooling through the heat exchanger
D) absorbing water vapour in the absorber
E) going through the discharge valve
D) absorbing water vapour in the absorber
What is the name of the heat recovery system that consists of two finned tube heat exchangers? A) a runaround system B) a heat valve C) a heat pump D) a heat tube E) a thermal wheel
A) a runaround system
When a boiler is removed from service, it can be drained once the temperature reaches approximately: A) 150*C B) 30*C C) 50*C D) 90*C E) 70*C
D) 90*C
Which of these statements about heat pumps is true?
A) the units discharge heat to the water piping during the cooling mode
B) the piping must be insulated
C) the water temperature is below the dew point of the room air
D) condensate drains from each unit are not necessary
E) the refrigeration system is cooled by freon, such as R-12
A) the units discharge heat to the water piping during the cooling mode
Modulating combustion control will:
A) change air and fuel flow proportionally to steam pressure change
B) always be at setpoint when demand is at 50%
C) alter only the air flow if a selector station is on manual
D) respond to changes in atmospheric pressure
E) always be a cascading control system
A) change air and fuel flow proportionally to steam pressure change
The two major types of refrigeration systems are: A) frosting and non-frosting B) commercial and residential C) type I and type II D) indirect and direct E) high pressure and low pressure
D) indirect and direct
One of the advantages of using natural gas as a fuel in a boiler is: A) no storage space is required B) low cost C) abundance in supplies D) portability E) no standby fuel is necessary
A) no storage space is required
Refrigerant is: A) not miscible with oil B) mostly used in packing plants C) corrosive on copper D) corrosive on aluminum E) a heat transferring medium
E) a heat transferring medium
A CRT trend display:
A) mimics a trend chart
B) is dedicated to a single process
C) is limited to displaying a fixed or non adjustable time period
D) allows a view of only one process variable at a time
E) is normally mounted beside the final control element
A) mimics a trend chart
A main advantage of steam grid humidifiers over steam pan humidifiers in HVAC systems is:
A) steam grid humidifiers can use inexpensive 2-position controls
B) there is minimal response time lag with steam grid humidifiers
C) steam grids can achieve higher relative humidity
D) steam grids do not require humidistats
E) steam grid humidifiers require less space
B) there is minimal response time lag with steam grid humidifiers
Chain blocks are designed: A) for horizontal use B) with the top hook as the strongest C) with a very low mechanical advantage D) with the hooks stronger than the chain E) for lifting very long objects
B) with the top hook as the strongest
Modern radiators are usually made of: A) steel B) cast iron C) stainless steel D) copper E) brass
A) steel
The process of vaporization of gasoline for use in an internal combustion engine is known as: A) combustion B) atomization C) oxidization D) carburetion E) priming
D) carburetion
In the lithium bromide refrigeration system, what is the function of the concentrator (generator)?
A) to exchange heat between the high temperature refrigerant vapour and the atmosphere
B) to increase the absorbency potential of used absorbent
C) to speed up the evaporation of the refrigerant
D) to cool the concentrated absorbent
E) to cool the refrigerant vapour
B) to increase the absorbency potential of used absorbent
The Venturi tube in the atmospheric burner mixing head has a:
A) gradually decreasing cross-sectional area
B) gradual increasing cross-sectional area
C) uniform cross-sectional area throughout
D) sharply increasing cross-sectional area
E) series of internal ridges, to promote mixing
B) gradual increasing cross-sectional area
The face velocity of a heating or cooling coil is the:
A) velocity of the supply water to the coil
B) velocity of the air before it enters the coil
C) velocity of the air after it leaves the coil
D) average velocity of the air flowing over the face area of the fun surface
E) velocity of the steam entering the coil
D) average velocity of the air flowing over the face area of the fun surface
In a closed vessel, the boiling point of a liquid can be raised by:
A) raising the liquid level in the vessel
B) lowering the pressure in the vessel
C) raising the pressure in the vessel
D) lowering the liquid level in the vessel
E) raising the temperature in the vessel
C) raising the pressure in the vessel
A safety control designed to protect the chiller from freezing is the: A) vane closed switch B) low oil pressure shut down switch C) motor demand limiter D) chilled water flow switch E) purge unit
D) chilled water flow switch
Centrifugal pumps convert rotating mechanical energy into kinetic energy then:
A) discharge the kinetic energy
B) back to mechanical energy
C) absorb the energy
D) into potential energy in the form of pressure
E) into centrifugal force
D) into potential energy in the form of pressure
The dry-bulb temperature scale is read on a psychrometric chart along the:
A) left vertical axis
B) right vertical axis
C) saturation line and sloping downward to the right
D) top horizontal axis
E) horizontal axis on the bottom of the chart
E) horizontal axis on the bottom of the chart
Which of the following statements about a constant pressure water system that has a pneumatic tank is false?
A) water entering directly into the pump suction is discharged into a pressurized tank
B) this system is primarily used in larger buildings
C) a system controller automatically starts a standby pump in the event of pump failure
D) the system has a pressure regulator to maintain a relatively constant pressure above the water level inside the tank
E) air must continuously be introduced into the tank
B) this system is primarily used in larger buildings
Push nipples:
A) connect radiator sections together
B) are tapered in the middle
C) are used to connect pipes together in a heating system
D) seal tighter than unions
E) have decreasing cross-sectional areas from one end to the other
A) connect radiator sections together
Most conductors tend to:
A) increase in resistance with increase in temperature
B) decrease in resistance with increase in temperature
C) shrink when heated
D) increase in resistance when decreased in length
E) increase in resistance over time
A) increase in resistance with increase in temperature
Infrared heaters are used in: A) theatres B) lecture halls C) libraries D) skating rinks E) offices
D) skating rinks
With antifriction bearings using grease, the bearings:
A) must be cleaned twice as often as oil-lubricated bearings
B) are cleaned every two years
C) are cleaned less often than oil-lubricated bearings
D) never require cleaning
E) last twice as long as oil-lubricated bearings
C) are cleaned less often than oil-lubricated bearings
Ammonia refrigerants:
A) have high sensible heat capacity
B) mix well with oil
C) are very expensive
D) are well suited for industrial refrigeration
E) are ideally suited to copper piping system
D) are well suited for industrial refrigeration
A "U" tube manometer may be filled with: A) a granular substance B) nitrogen C) heavy oils D) ethyl alcohol E) light oils
E) light oils
A very popular packaged boiler gas burner is the: A) ring burner B) in-duct burner C) post mix atmospheric burner D) mechanical atomizing burner E) cluster nozzle burner
A) ring burner
A steam boiler must be equipped with two low water fuel cut-off devices when the boiler: A) has over 47 m2 of heating surface B) has dual fuels C) is not continuously attended D) uses coal as fuel E) has two burners
C) is not continuously attended
According to code, the scale of a pressure gauge for a steam heating boiler shall be graduated between: A) 100 to 300 kPa B) 200 to 414 kPa C) 200 to 300 kPa D) 125 to 325 kPa E) 230 to 414 kPa
B) 200 to 414 kPa
In a refrigeration system controlled by a high pressure float valve, excessive refrigerant charge will cause:
A) liquid carry over to the compressor
B) the float chamber to become flooded
C) the evaporator to be starved of refrigerant
D) frost formation on the evaporator
E) the compressor to run continuously
A) liquid carry over to the compressor
In order to keep humidifiers in top working condition, the plates of plate type units should be cleaned by soaking them in a slightly acidic solution and them washing them in soapy water to remove: A) dirt B) grease C) soot D) mineral salts E) corrosion on the plate
D) mineral salts
The injection pump of a Diesel engine is driven by: A) piston action B) the governor C) the wrist pin D) the gudgeon pin E) a camshaft
E) a camshaft
Ohms law can be stated as: A) E=IR B) R=I/E C) I=R/E D) volts equals ohms divided by amperes E) watts times ohms equals volts
A) E=IR
When reading the dials of a power meter, read:
A) them in the sequence shown by the letters under each
B) them from left to right
C) the ones that rotate clockwise first
D) them from right to left
E) them only at the request of the utility company
D) them from right to left
With regard to fan capacity control, which of the following devices has a de-clutching feature? A) a fluid drive B) an outlet damper control C) a variable inlet vane control D) a variable speed motor control E) a V-belt drive
A) a fluid drive
Which of the following statements about vacuum breakers is false?
A) they are used to prevent freeze-ups caused by negative pressure in steam heating coils
B) the vacuum breaker must be installed before the control valve and as near as possible to the outlet connection of the coil
C) check valves used as vacuum breakers may be left open to atmosphere
D) check valves used as vacuum breakers may be connected to the condensate return header
E) vacuum breakers are essential for satisfactory functioning of steam traps
B) the vacuum breaker must be installed before the control valve and as near as possible to the outlet connection of the coil
Specific humidity is the:
A) ratio of the actual amount of water vapour present in the air to the amount of water vapour the air can contain when it is saturated
B) same as specific volume of humid air
C) actual moisture content of air expressed as kg of moisture per kg of dry air
D) ratio of dry air to moisture
E) moisture content of 1 kg of air at 100% relative humidity and atmospheric pressure
C) actual moisture content of air expressed as kg of moisture per kg of dry air
The back flow prevention method consisting of two independent check valves with an automatic operating pressure differential relief valve located between them is called: A) air gap back flow prevention B) double check valve C) reduced pressure principle device D) atmosphere vacuum breaker E) PVB
C) reduced pressure principle device
Electronic filters will remove: A) all particles from the air B) fine particles from the air C) odours D) smoke E) carbon monoxide
B) fine particles from the air
When the outdoor air damper of an HVAC system opens to increase the flow of fresh air, the return air damper:
A) opens to reduce the recirculated air
B) opens to increase the recirculated air
C) closes to increase the recirculated air
D) closes to reduce the recirculated air
E) modulates to maintain building static pressure
D) closes to reduce the recirculated air
If the chilled water temperature drops approximately 2.5-3*C below the chilled water temperature set point, the chilled water low temperature cut out will: A) start the compressor B) shut down the compressor C) stop the chilled water pumps D) shut down the cooling tower fan E) start the condenser pump
B) shut down the compressor
To calculate the heat gain from fluorescent lighting, add the wattage ratings of the lamps and multiply by: A) 0.2 B) 0.5 C) 4.1 D) 1.2 E) 2.1
D) 1.2
The oil pressure failure switches of a mechanical refrigeration system:
A) keep the compressor oil pressure at a level where the oil will not freeze
B) prevent compressor start up if the oil heater fails
C) separate refrigerant dissolved in the oil from the lubricant
D) shut down the compressor when the oil pressure drops below the minimum required value
E) keep the oil from freezing at low pressure
D) shut down the compressor when the oil pressure drops below the minimum required value
When shutting down a boiler for internal cleaning, you should:
A) shut down the boiler, then fill it completely with chemically treated water
B) shut off the fire, drain, open up and flush
C) allow the boiler to cool, then drain, open up, and flush it
D) shut off the fire and flush with cold water to cool it off
E) let it stand for a couple of days then drain
C) allow the boiler to cool, then drain, open up, and flush it
Clamp-on ammeter readings may be inaccurate if: A) jaws are dirty of misaligned B) circuit voltage is too high C) circuit resistance is too low D) circuit power is too high E) conductor insulation is too thick
A) jaws are dirty of misaligned
High efficiency furnaces and heaters range in annual fuel utilization efficiency (AFUE) from: A) 94-98% B) 80-98% C) 70-75% D) 60-70% E) 50-60%
B) 80-98%
Castle nuts are used: A) to simplify assembly and disassembly B) to hold shims in place C) with a square pin D) for locking square nuts in place E) with a split pin or cotter pin
E) with a split pin or cotter pin
The stator of an alternator is built of \_\_\_\_\_ mounted in a frame. A) copper alloys B) silicon steel C) carbon ring D) armature conductors E) non-metallic materials
B) silicon steel
The voltage required to force a current of 15A through a resistance of 5 ohms will be \_\_\_V. A) 0.33 B) 3 C) 7.5 D) 33 E) 75
E) 75
The outside air is a temperature of -25*C, and is saturated. This air is drawn into the building and heated to 21*C. What is the relative humidity of the air after passing through the heating coil? (Air at -25*C holds a maximum of 0.0005 kg of moisture per kg of water, and air at 21*C holds a maximum of 0.015 kg of moisture per kg of water) A) 3.3% B) 0.15% C) 0.5% D) 10.6% E) 4.5%
A) 3.3%
The propeller axial flow fan:
A) produces low capacity, low pressure air movement
B) finds application in unit heaters, air cooled condensers, and as an exhaust fan for ventilation purposes
C) is used in commercial air conditioning ducting
D) requires the least power at minimum air delivery
E) is used in ducted air distribution systems
B) finds application in unit heaters, air cooled condensers, and as an exhaust fan for ventilation purposes
Thermocouples are connected in series to:
A) monitor more than one flame source
B) increase the sensitivity of the detection system
C) generate a higher voltage
D) provide redundancy if one should fail
E) create what is called a “flame rod”
C) generate a higher voltage
The standard refrigeration cycle is used to compare refrigerants and machines operating under comparable conditions. These standard conditions are: A) 1030 kPa and atmospheric pressure B) 30*C condensing and -15*C evaporating C) 30 kPa and atmospheric pressure D) -30*C condensing and 15*C evaporating E) 30 kPa and atmospheric temperature
B) 30C condensing and -15C evaporating
A bourdon tube may be manufactured in the shape of a helix so that _____ than a standard bourdon tube.
A) its final output has less travel
B) they can fit in narrower enclosures
C) higher pressures can be sensed
D) it is more powerful, and has a greater degree of rotation
E) it will be less sensitive to minor pressure variations
D) it is more powerful, and has a greater degree of rotation
If an electrical \_\_\_\_\_ is placed across a conductor, the electrons will drift from the negative and towards the positive end of the conductor. A) potential B) current C) resistance D) wire E) meter
A) potential
At the end of the pre-purge period, the combustion programmer: A) shuts down B) opens the main fuel valve C) closes the pilot valve D) ends the ignition trial E) energizes the ignition transformer
E) energizes the ignition transformer
A pneumatically actuated control valve which opens on air failure has a:
A) direct acting actuator and direct acting valve
B) direct acting actuator and reverse acting valve
C) reverse acting actuator and direct acting valve
D) is typically used for a burner firing rate control valve
E) is typically used for a feedwater control valve
A) direct acting actuator and direct acting valve
A control room operator notices that the stack temperature of the hot oil heater is increasing rapidly. The operator should:
A) activate the emergency shutdown
B) call the shift boss on the intercom
C) send an operator out to see if there is smoke coming from the oil heater stack
D) wait to see if the temperature will come down again
E) alert the fire department
A) activate the emergency shutdown
Which of the following is a disadvantage of heat pipe heat recovery systems?
A) heat pipes have high maintenance requirements
B) heat pipes suffer from cross-contamination of the air streams
C) heat pipes have high power consumption
D) a side-by-side duct arrangement is needed
E) the necessary pumps and piping are complicated and expensive to install
D) a side-by-side duct arrangement is needed
An automatic boiler ON/OFF or operating control switch has an adjustment for pressure set point and another for: A) a differential between the two B) manual or automatic control C) for rate of modulation D) high steam pressure limit E) rate of feedback
A) a differential between the two
Tie breakers are used to:
A) allow the interconnection of two power sources without placing them in parallel
B) break the circuit in case of overload
C) protect the transformer from the power source
D) protect the plant service bus from the power source
E) connect the plant load to the power source
A) allow the interconnection of two power sources without placing them in parallel
Coking of the oil in hot oil heater tubes will begin to occur if:
A) the oil becomes too thick
B) there is too much water in the oil
C) the oil temperature becomes excessively high
D) the oil flow becomes excessively high
E) the surge tank level becomes low
C) the oil temperature becomes excessively high
Shaft sealing carbon glands are: A) lubricated by the main oil pump B) limited to a temperature of 250*C C) replaced monthly due to erosion D) self-lubricating E) sprayed with Monel
D) self-lubricating
A two-position controller compares conditions to a set point and:
A) starts or stops a process
B) a controller output signal
C) modulates the final control element
D) automatically readjusts the set point
E) maintains the final control element position at 50%
A) starts or stops a process
The lowest schedule for large diameter pipe (above 25.4 mm) in a hot oil system should be schedule \_\_\_\_. A) 20 B) 40 C) 80 D) 120 E) 160
B) 40
One of the advantages of gas-fired infrared heating over other types of heating systems is:
A) it can heat a large volume enclosure with little fuel
B) it requires no fuel handling equipment
C) it eliminates the need for ventilation
D) it can provide effective spot heating
E) it can be used efficiently as the main heating source fora large building
D) it can provide effective spot heating
The scale on the dial of the pressure or altitude gauge on a hot water heating boiler shall be graduated approximately to not less than \_\_\_\_ times the maximum allowable working pressure. A) 0.5 B) 1 C) 1.5 D) 2 E) 2.5
C) 1.5
The accessory that maintains efficient heat transfer by collecting oil that coats the tubes of the condenser is called: A) strainer B) a strainer-drier C) an oil scrubber D) a filter E) an oil separator
E) an oil separator
The maximum voltage generated by a single loop DC generator occurs when the conductor is cutting the magnetic lines of force at an angle of: A) 0* B) 45* C) 90* D) 120* E) 180*
C) 90*
Which of the following statements about two-pipe arrangements is false?
A) the arrangement is the least costly
B) piping is connected to the boiler during winter
C) piping is connected to the chiller during summer
D) the arrangement is made up of a supply and return connection to a single coil
E) the system can heat and cool at the same time
E) the system can heat and cool at the same time
A pump is capable of suction lift due to:
A) its ability to convert kinetic energy into potential energy
B) the speed at which it operates
C) its input power
D) its size
E) atmospheric pressure
E) atmospheric pressure
The furnace refractory in a boiler should be ____ to prolong its life.
A) wash coated with a dilute solution of heat resistant cement
B) painted with heat resistant paint
C) oiled
D) wire brushed
E) washed with a high pressure hose
A) wash coated with a dilute solution of heat resistant cement
A valve which gives good throttling action, takes less actuator force, but does not seal well is a: A) double seated valve B) reverse acting valve C) multiple disc valve D) single seated valve E) direct acting valve
A) double seated valve
Some water closets are provided with flush tanks while others are equipped with: A) float valves B) flushometers C) ball cocks D) drain valves E) flood valves
B) flushometers
Shaft sealing of small steam turbines is done with: A) O-rings B) compressed air C) carbon rings D) labyrinth glands E) mechanical seals
C) carbon rings
The heat recovery system which makes use of an underground heat exchange coil is called a: A) run around system B) thermal wheel C) heat tube D) heat pump E) heat pipe
D) heat pump
On a multiple steam boiler heating system, a stop valve must be placed at each boiler outlet to:
A) permit slower system warm ups
B) allow the boilers to be isolated from the system
C) prevent steam from entering another boiler
D) allow each boiler to supply only a part of the system
E) permit different system pressures
B) allow the boilers to be isolated from the system
The compressed air used as atomizing air in the air atomizing oil burner is also called: A) secondary air B) primary air C) pre-mixed air D) combustion air E) post-compressed air
B) primary air
When using Fleming’s left hand rule, the index finger represents:
A) magnetic flux direction, for generators
B) conductor motion direction, for motors
C) conductor motion direction, for generators
D) flux direction, for motors
E) direction of current flow, for motors
D) flux direction, for motors
In a centrifugal compressor, the kinetic energy is converted to potential energy in the: A) volute, diffuser, or both B) intercooler C) diffuser only D) compressor cavity E) volute only
A) volute, diffuser, or both
The flow arrangement best suited for hot water coils used to heat sub-freezing air is:
A) the counter flow arrangement because it is more efficient
B) the parallel flow arrangement because it gives better protection against freezing
C) one in which the cold air enters the coil where the coldest water is flowing
D) the half serpentine
E) the triple bypass flow arrangement
B) the parallel flow arrangement because it gives better protection against freezing
Taper, plug, and bottoming are types of: A) wrenches B) dies C) files D) punches E) taps
E) taps
When a pump discharges into a vessel operating at 300 kPa, the 300 kPa is referred to as: A) dynamic head B) equivalent head C) discharge head D) friction head E) total head
B) equivalent head
A thermocouple: A) consists of two similar wires B) produces an electrical signal C) senses infrared light from the flame D) is made of several thermopile so connected in series E) is also called a "pilot-stat"
B) produces an electrical signal
Refrigerants will evaporate when the:
A) pressure is increased
B) temperature is increased to saturation temperature
C) they are diluted
D) temperature is reduced below saturation temperature
E) heat is removed from them
B) temperature is increased to saturation temperature
With all other factors being equal, a counter flow cooling tower \_\_\_\_\_ as a cross flow cooling tower. A) is not as tall B) has much less cooling capacity C) requires less floor space D) requires less fan power E) has a lower pressure drop
C) requires less floor space
Lock washers:
A) prevent marring of the work surface
B) distribute the lock nut force
C) allow oversized bolts or nuts to be used
D) reduce the chances of unwanted turning of the nut or bolt
E) prevent the equipment from being dismantled
D) reduce the chances of unwanted turning of the nut or bolt
The specific humidity scale of a psychrometric chart is along the:
A) bottom horizontal axis
B) right side vertical axis
C) top horizontal axis at the top of the chart
D) left saturation line
E) left side vertical axis and left side
B) right side vertical axis
Boiler blowoff piping:
A) can be reduced in size after the blowdown valves
B) must be full size to the point of discharge
C) must be at least 51 mm in size
D) can have valves of a smaller size than piping
E) may discharge to the sewer system
B) must be full size to the point of discharge
A steam heating boiler that is to be shut down for six months during the summer, should be:
A) drained, thoroughly dried out, have desiccant placed inside, and be left open
B) drained, thoroughly dried out, have desiccant placed inside, and be closed up
C) left with the water at normal working level but opened up to atmosphere
D) left with the water at normal working level and pressurized with air to 50 kPa
E) filled completely with water and the vent left open to atmosphere
B) drained, thoroughly dried out, have desiccant placed inside, and be closed up
