Questão 1
Questão
What is the volume of a room that measures 10ft by 20ft with an 8ft ceiling
Questão 2
Questão
What is the CFM requirement for a 1800 ft2 house with 8 ft ceilings, if five air changes per hour are needed?
Questão 3
Questão
what is them CFM requirement for an 2400 ft2 house with 8 ft ceilings, if five air changes per hour are needed.
Questão 4
Questão
what is the cross sectional area of a 10-in round metal duct
Responda
-
79 in2
-
200 in2
-
314 in2
-
418 in2
Questão 5
Questão
how fast does air with a velocity pressure of 0.20in. w.g. move through a round duct
Responda
-
400ft/min
-
1200ft/min
-
1600ft/min
-
1800ft/min
Questão 6
Questão
how fast does air with a velocity pressure of 0.20in w.g. move through a square duct?
Responda
-
400 ft/min
-
1200 ft/min
-
1600 ft/min
-
1800 ft/min
Questão 7
Questão
What is the advantage of using a tube cutter to cut copper pipe?
Responda
-
it can cut hard or soft copper
-
it leaves no metal shavings to contaminate the system
-
it produces a clean, square cut
-
all of the above
-
only B & C
Questão 8
Questão
spring-type benders may be used on ________?
Responda
-
soft drawn copper
-
hard copper
-
all copper pipe
-
steel pipe
Questão 9
Questão
a flaring tool is used to _________.
Questão 10
Questão
a swaging tool is used to _________.
Questão 11
Questão
what is one of the advantages of a glass-stem thermometer?
Questão 12
Questão
in discussing human comfort, the temperature most commonly referred to is __________.
Responda
-
dew point
-
dry-bulb
-
wet-bulb
-
fahrenheit
Questão 13
Questão
a sling psychrometer uses two glass-stem thermometers. one measures dry-bulb, and the other measures ______.
Responda
-
dew point
-
enthalpy
-
relative humidity
-
wet-bulb
Questão 14
Questão
a standard refrigeration manifold uses what type of element to measure pressure?
Responda
-
bellows
-
bourdon tube
-
diaphragm
-
spring
Questão 15
Questão
what is the pressure range of a standard compound gauge on a refrigeration manifold?
Responda
-
0 to 350 psi
-
0 to 500 psi
-
30in. Hg to 350 psi
-
30in. Hg to 500 psi
Questão 16
Questão
what is the best tool for removing moisture and noncondensibles from a system before adding refrigerant
Responda
-
manifold gauge
-
micron analyzer
-
recovery machine
-
vacuum pump
Questão 17
Questão
a vacuum gauge reads pressure in ______.
Responda
-
inches of mercury
-
inches of water
-
microns
-
psia
-
psig
Questão 18
Questão
which of the following is NOT a method of leak detection?
Responda
-
soap bubbles
-
electronic
-
micronic
-
ultrasonic
Questão 19
Questão
to prevent the release of refrigerant into the atmosphere, while removing it from a system what tool is used?
Responda
-
recovery machine
-
recycling machine
-
reclaim machine
-
vacuum pump
Questão 20
Questão
an anemometer uses a small fan blade to measure ______?
Responda
-
air pressure
-
air velocity
-
air volume
-
static pressure
Questão 21
Questão
what is one of the advantages using silver rods for brazing copper?
Questão 22
Questão
what agency regulates cylinders and chemicals transported in a service vehicle?
Responda
-
ASHRAE
-
DOT
-
EPA
-
OSHA
-
ICE
-
DMV
-
LOL
-
YOLO
Questão 23
Questão
What is the maximum safe storage temperature of a refrigerant cylinder filled to 80% capacity by weight?
Questão 24
Questão
which of the following classification of fire extinguishers should be used for an electrical fire?
Questão 25
Questão
which of the following categories could be considered a hazardous atmosphere in a confined space?
Responda
-
asphyxiation
-
flammable
-
toxic
-
all of the above
Questão 26
Questão
if a ladder is placed against a wall that is 20 ft tall, what is the proper distance away from the wall for the base of the ladder?
Questão 27
Questão
what is one of the most important safety precautions that you can take when working on electrical equipment
Responda
-
disconnect and lockout power before starting unless testing requires the power to be on
-
keep one hand in your pocket while working on the power
-
label all hot wires
-
wear gloves suitable for high voltages
Questão 28
Questão
when does a ground fault circuit interrupter open an electric circuit?
Responda
-
when current travels through a ground path other then the neutral
-
when the circuit is overloaded
-
when there is a short circuit
-
all of the above
Questão 29
Questão
a natural cooling process produced by moisture on the skin changing to low pressure steam is called _______.
Responda
-
conduction
-
convection
-
evaporation
-
radiation
Questão 30
Questão
during the heat season, human comfort can be enhanced without changing the temperature of the air by _________.
Questão 31
Questão
during the cooling season, dampers on bypass humidifiers should be ___________.
Responda
-
completely closed
-
completely open
-
set to 25% open
-
set to 50% open
Questão 32
Questão
all matter can exist as _________
Responda
-
liquid
-
gas
-
solid
-
all of the above
Questão 33
Questão
stored energy is called ____________ energy
Responda
-
controlled
-
kinetic
-
potential
-
quantum
Questão 34
Questão
heat that you can feel and measure directly with a thermometer is called ___________ heat.
Responda
-
absolute
-
latent
-
sensible
-
super
Questão 35
Questão
the heat energy change associated with a phase (state) change is called ________.
Responda
-
absolute
-
latent
-
sensible
-
super
Questão 36
Questão
the amount of heat (BTU) needed to raise the temperature of 1lb of a substance 1 degree is call the ___________ heat of the substance.
Responda
-
absolute
-
latent
-
sensible
-
specific
Questão 37
Questão
the latent heat of infusion is the amount of energy required to change 1 lb of a substance from ________ phase to the ________ phase without changing its temperature.
Responda
-
liquid, vapor
-
liquid, solid
-
solid, vapor
-
vapor, liquid
Questão 38
Questão
at 32F, 1lb of ice can changed to 1lb of water by adding _____ BTU.
Questão 39
Questão
at 212F 1lb of ice can be changed to 1 lb of steam by adding ______ Btu.
Questão 40
Questão
when liquid and vapor phases of a substance exist together, and no more liquid can vaporize without more energy being added, the vapor is said to be _______.
Responda
-
saturated
-
stabilized
-
subcooled
-
superheated
Questão 41
Questão
when a vapor is heated to a temperature higher than its saturation point, both the added heat and the temperature above saturation are called _________.
Responda
-
latent heat
-
sensible heat
-
specific heat
-
super heat
Questão 42
Questão
the process of molecules escaping from the surface of a liquid is called ________.
Responda
-
condensation
-
evaporation
-
saturation
-
subcooling
Questão 43
Questão
the process of a solid turning directly into a vapor without going through the liquid state is called _______.
Responda
-
saturation
-
subcooling
-
sublimation
-
superheating
Questão 44
Questão
the continuous movement of molecules within a liquid or gas is called ______ energy.
Responda
-
atomic
-
kinetic
-
potential
-
stored
Questão 45
Questão
enthalpy includes both _________ and ________ heat energy.
Responda
-
latent, sensible
-
latent, specific
-
sensible, specific
-
specific, absolute
Questão 46
Questão
the measurement of force that gravity exerts is called?
Responda
-
mass
-
specific matter
-
volume
-
weight
Questão 47
Questão
the amount of matter in a substance is called
Responda
-
gravity
-
mass
-
volume
-
weight
Questão 48
Questão
weight per unit of volume or mass per unit of volume is called?
Responda
-
density
-
specific gravity
-
specific mass
-
specific volume
Questão 49
Questão
volume per unit of mass or weight is called?
Responda
-
specific volume
-
specific mass
-
specific gravity
-
density
Questão 50
Questão
under standard conditions, air weights approximately _______ lb/ft3
Questão 51
Questão
solve to find the fahrenheit temperature corresponding to 30 celcius .
Questão 52
Questão
solve to find the fahrenheit temperature corresponding to 20 celcius
Questão 53
Questão
solve to find celsius temperature corresponding to 80 F
Questão 54
Questão
solve to find the Celsius temperature corresponding to 60
Questão 55
Questão
if the absolute temperature of a gas is doubled, under constant pressure the volume will be _______.
Responda
-
cut in half
-
doubled
-
increased by 25%
-
unchanged
Questão 56
Questão
what is the new volume of 1 ft3 of air at 0f when heated to 100f
Questão 57
Questão
if gauge pressure reads 30 psi, what is the corresponding absolute pressure?
Questão 58
Questão
the law that applies to the total pressure exerted by a mixture of gases or vapors is called __________ law.
Responda
-
boyles
-
charles
-
daltons
-
newtons
-
daves
Questão 59
Questão
an ampere is a measurement of what?
Responda
-
electrical charge
-
electron flow rate
-
opposition to current
-
potential energy
Questão 60
Questão
voltage is best defined as the ______?
Responda
-
amount of power being used in a circuit
-
force that moves electrons through a circuit
-
magnetic field surrounding a conductor
-
resistance to the flow of electrons
Questão 61
Questão
current in a circuit is limited by ______ ?
Responda
-
heat
-
resistance
-
temperature
-
voltage
Questão 62
Questão
a substance that permits the free movement of electrons is called a(n) ____________.
Responda
-
conductor
-
insulator
-
resistor
-
semiconductor
Questão 63
Questão
which of the following conductors would have the least resistance?
Responda
-
a long, large diameter conductor
-
a long, small diameter conductor
-
a short, large diameter conductor
-
a short, small diameter conductor
Questão 64
Questão
if the voltage in a circuit is doubled and the resistance remains the same, the current will _________.
Responda
-
drop to zero
-
be cut in half
-
double
-
stay the same
Questão 65
Questão
what is the voltage of a circuit if the resistance is 5 ohms and the current is 5 A?
Questão 66
Questão
A circuit has a voltage of 10 V and a current of 5 A. what is the resistances
Questão 67
Questão
the total resistance of a series circuit is equal to the _________.
Questão 68
Questão
the total current in a parallel circuit is _______.
Responda
-
measured and divided by the number circuit paths
-
measured only at the first circuit path
-
the sum of the currents through the individual paths
-
the total of the first and the last circuit paths
Questão 69
Questão
the rate of doing work is called?
Responda
-
amperage
-
electricity
-
power
-
voltage
Questão 70
Questão
one kilowatt is equal to?
Responda
-
10 W
-
100 W
-
1,000 W
-
10,000 W
Questão 71
Questão
which of the following equations is used to solve for electric power
Responda
-
P = E x I
-
P = I2 x R
-
P = E2 / R
-
All of the above
Questão 72
Questão
what is the power in a circuit that has a current of 10 A and a resistance of 10 ohms
Questão 73
Questão
The voltage induced in each turn of the secondary coil of a transformer is __________?
Responda
-
half the voltage induced per turn of the primary coil
-
twice the voltage induced per turn of the primary coil
-
the same as the voltage induced per turn of the primary coil
-
determined by the ratio of turns in the primary to turns in the secondary
Questão 74
Questão
the load rating of a transformer is stated in ________.
Responda
-
amperes
-
volts
-
volt-amperes
-
watts
Questão 75
Questão
an ac induction motor consists of a stationary part called the _______ and a rotating part called the ________.
Responda
-
field, armature
-
primary winding, secondary winding
-
start winding, run winding
-
stator, rotor
Questão 76
Questão
what is the synchronous speed of a three-phase motor that has six poles and is operated on 60-Hz alternating current?
Responda
-
1200 rpm
-
3600 rpm
-
4320 rpm
-
7200 rpm
Questão 77
Questão
how does the power factor of an inductive motor affect efficiency?
Responda
-
the lower the power factor, the less efficient the motor is
-
the lower the power factor, the more efficient the motor is
-
the higher the power factor, the less efficient the motor is
-
the power factor has no effect on efficiency of the motor
Questão 78
Questão
which of the following single-phase ac motors does not have a start winding?
Questão 79
Questão
a centrifugal switch open the start winding circuit when a capacitor-start motor reaches approximately __________ % of its full speed.
Responda
-
50%
-
60 - 70 %
-
75 - 80 %
-
90 - 100 %
Questão 80
Questão
a run capacitor is always connected to the ________ and __________ terminals.
Responda
-
primary, secondary
-
run , common
-
start, common
-
start, run
Questão 81
Questão
terminal No.1 on all potential relays is always connected to the __________.
Responda
-
common terminal
-
run terminal
-
start capacitor
-
start terminal
Questão 82
Questão
the coil of a voltage relay is between terminal _________ and terminal ________ of the relay
Questão 83
Questão
what type of ac motor has the highest starting torque and the greatest efficiency?
Questão 84
Questão
how many terminals does a dual-voltage three phase motor have?
Questão 85
Questão
the primary function of a wiring diagram is to ________.
Responda
-
aid the technician in finding the problem
-
help the owner repair the problem
-
provide the location of the components
-
reduce repair time
Questão 86
Questão
how many functions is an individual circuit in a control system designed to control
Questão 87
Questão
the five basic components common to all schematics are a power supply, a path, a load, a legend, and a ___________?
Responda
-
contactor
-
relay
-
switch
-
thermostat
Questão 88
Questão
the intention of the overall schematic is to show how the circuit _________.
Responda
-
components are connected
-
fails
-
functions
-
looks
Questão 89
Questão
the type of schematic that provides the most helpful troubleshooting information for the service technician is the __________ diagram.
Responda
-
connection
-
installation
-
ladder
-
pictorial
Questão 90
Questão
devices that consume power and convert it to some other form of energy, such as motion or heat are ____________.
Responda
-
contacts
-
fuses
-
loads
-
transformers
Questão 91
Questão
the normal dividing line for voltage changes in a schematic is the _________.
Responda
-
contactor
-
fuse
-
relay
-
transformer
Questão 92
Questão
the part of a schematic that lists and explains the system components is called the _________.
Responda
-
appendex
-
guide
-
index
-
legend
Questão 93
Questão
This symbol shown below represents a?
Responda
-
double-pole, double-throw switch
-
double-pole, single-throw switch
-
single-pole, double-throw switch
-
single- pole, single-throw switch
Questão 94
Questão 95
Questão
relays and contactors are ___________ control switches.
Responda
-
electrically operated
-
manually operated
-
pressure- activated
-
temperature- activated
Questão 96
Questão
a(n) _________ circuit allows the same current to flow through all of the components.
Questão 97
Questão
a(n) _______________ circuit has multiple paths for current flow.
Questão 98
Questão
what type of circuits are primarily used in control and safety applications?
Responda
-
continuous
-
parallel
-
series
-
series-parallel
Questão 99
Questão
when testing with a voltmeter, you should place the meter __________.
Responda
-
in series with the circuit being tested
-
in parallel
-
on the highest possible setting
-
on the lowest possible setting
Questão 100
Questão
what does a resistance reading of 0 ohms indicate.
Questão 101
Questão
when you use an ohm meter, the circuit being measured must be _________.
Questão 102
Questão
when you test a switch with an ohm meter, a reading of ________ indicates that the switch is closed
Responda
-
0 ohms
-
24 V
-
120 V
-
infinity
Questão 103
Questão
on all meters, digital and analog, the scale used should indicate the measurement ___________
Responda
-
close to the bottom of the range
-
close to the middle of the range
-
close to the top of the range
-
anywhere within the range
Questão 104
Questão
when testing across a closed switch in an energized circuit, you should read __________.
Responda
-
0 ohms
-
infinite resistance
-
0 V ac
-
120 V ac
Questão 105
Questão
when using a standard clamp-on ammeter, you should ________ before taking a reading.
Responda
-
disconnect all of the wires in the circuit being tested
-
make sure that the jaws are closed
-
make sure that the jaws are open
-
shut down and lockout the equipment being tested
Questão 106
Questão
when testing compressor windings, you take the following readings:
C to R: 2 ohms
C to S: infinite resistance
R to S: infinite resistance
whats is the diagnosis?
Responda
-
the compressor is good
-
the run winding is shorted
-
the start winding is shorted
-
the start winding is open
Questão 107
Questão
capacitance meters must be used on capacitors _________.
Questão 108
Questão
when testing a thermostat wire that has been removed from a circuit, you measure 0 ohms between red and white. this indicates that ______________.
Questão 109
Questão
when testing with an ammeter, you should place the meter _____________.
Responda
-
in series with the circuit being tested
-
in parallel with the circuit being tested
-
on the highest possible setting
-
on the lowest possible setting