C 7 Flashcards
what is used for electrical energy
Capacitor
what device would you use to locate underground cables or conduit
Electronic metal detector
before using a keyhole saw to install recessed ceiling light, what do you do
drill a hole large enough for the saw blade
for a security alarm, the most cost-effective way to detect an intruder breaking through a wall or ceiling it to install
vibration detectors
vibration detectors in an alarm system are best installed on
walls
vibration detractors in a alarm system should be installed _____above floor level and________apart
4-5 feet—–2-5-6 feet
the portion of a circuit that extends beyond the final overcurrent device is called the
branch circuit
a cable with two insulated conductors concentric to each other is called
coaxial
one cycle represents
360 degrees
another term for an inductor is a
coil
an ohm represents the amount of electrical resistance that allows current to flow at the rate of on_____under a pressure of one_______
resistor
splices in doorbell wiring
may be made at any point in the circuit
you must keep stereo-speaker wires at least____away from exposed power wiring
2 inches
a circuit that controls other circuits or parts there of through devices such as relays is called a
remote-control circuit
a circuit that enegizes devices designed to give visual or audible signals is a called a
signal circuit
for a remote-control circuit, a transformer usually steps down the 120-volt supply to a nominal
24 Volts
a basic telephone system, the connection between the building to the central office is know as the
local loop
the proper location for a telphone outlet intended for an office desk phone is
the same height as the power box( 14” above the floor)
in a typical satelite antnna system, the reciever is connected to the television by
75-ohm coaxial cable
in a phone system, REN refers to the Ringer Equivalence number. Five 1 Ren phone equal 5 RENS. Ten 1/2 REN phones equal
5 RENS
Wiring used to ground a phone company’s incoming cable sheath and protector is no small than_____ or its equivalent
No. 14 AWG copper
a motorized master control device can typically control up to
25 circuits
troubleshooting a 120-volt outdoor lighting system. One of the fixtures does not light. After replacing the bulb, what is the next step
turn off the power and check with the voltage tester to make sure its off
troubleshooting a 120 volts outdoor lighting system. One of the fixtures does not light. Which of the following may be the problem
the lamp socket contact is faulty
the junction box wiring at the fixture is faulty
the circuit breaker is tripped
how do you care for someone that that has been shocked and has been freed from the equiptment
check to see if the victim is still breathing and if there is a heartbeat. If not apply CPR
cables installed in building locations other than plenums or riser must be type CMG or TYPE CM. However, the NEC allows several exceptions for type CMX communications cable-less that____in diameter
.25”
in new constrution, smoke detectors are powered by
120- V ac circuit wiring
how should you care for a victim in a state of shock
keep victim lying down to improve circulation and reduce paing an call for emergency medical assitance
in which if the following locations may you not use rigid PVC as a conduit
in an HVAC duct
No. 18 copper conductors run in vertical raceways must be supported every____
100 ft
No. 16 copper conductors run in vertical raceways must be supported every____
100 ft
No. 0000 AWG copper conductors run in vertical raceways must be supported every____
80 feet
when would an electrican be likely to get the most use of an adjustible cresecent wrench
when installing and removing compression couplings on thinwall conduit
Nonmetalic wireways must be supported at least every
10 Ft
PVC conduit less than 1.25-inch nominal size must be supported at least every
3 ft
non-rigid metallic conduit must be supported at least every
10 ft
flexible metal conduit must be supported at least evey
4 1/2 feet
when installing the ground for a phone system, you should attach the ground to
a conductor system originally installed when the building was constructed.
a riser is
a vertical shaft that space two or more floors
Plenumn is
an air handling space where seveal ducts meet
where does a blue wire go in the low voltage system
to a relay
the primary battery of a smoke detector must
last one year before needing replacement
if any work is begun on the alarm panel of a cental station you must
restore the panel to normal opeartion as soon as possible
if your are installing a step-down transformer in a low voltage remote control system, which connections are required to be inside an enclosure
only the high voltage (powering wiring) conections
you insert telephone line tester into a wall jack so the number 2 is toward the stepped side of the jack. The red light goes on. That tells you
the polarity is reversed in Line 1
you insert telephone line tester into a wall jack so the number 2 is toward the stepped side of the jack. The yellow light goes on. That tells you
there is AC pwer on the line
sound sysem cables are allowed to fill a raceway to_____ of it capacity
75%
A generator produces electricity by
electromagnic induction
when using a keyhole saw you should use
very light pressure
sabersaws are designed to cut on the
upstroke
hacksaws are designed to cut on the
downstroke
in which tasks does a hacksaw perform least well
cutting rigid metal conduit
what would you generally use to Cut EMT
a hacksaw or a pipe cutter
bending conduit is best done with a
field hickey
why is a conduit bender the best tool to use to bend EMT
it keeps the interior volume of the pipe unchanged
which would you use to clear or check conduit before pulling cable
mandrel
what tool would you use to check that a pipe is adequately grounded
Megger
a device has a resistance of 12 ohms and draws 3 amps. According to Ohms law, what voltage should be supplied
36 volts
if a phone system is ringing on the main line, what is the color of the ring wire
red
for low voltage wiring, use rigid metal conduit to go through______for fire protection
concrete walls
you must use conduit when running wiring through
cement
what tool would you use to notch wooden studs, floor joints, etc for the passage of conduit
wood chiesel
what is the most practical alternative for running conductors between floors of an existing building
conduit
for a chime/bell system in a residence, it is standard practice to install
one pushbutton at each door
when measuring conduit for two 90 degree bends, you should
add the back-to back overshoot to the desired lenght
when designing a drawing a low voltage system
draw on new plans
what is the proper way to store tools at a job site
power-acutated tools must be kept in a locked container whenever unattened
why is cooper better that silver for electrical wiring
cheaper
the correct way to install wire-nuts is
strip ends the length of the wire-nut, twist tightly clockwise, use cutters to trim the ends even, then twist on the wire nut hand tight
the safety disconnect switch for a motorized equiptment must be located
within 50 feet of the motor and driven equipment
what is the the correct way to use a roto-or hammer drill
fast speed with as much presure as you can manage
when insalling a fire alarm panel and other devices attached to the panel
all devices must be approved by the authority having jurisdiction or listed for use with the panel
what type of switch is normally used to control a remote control relay
single pole, double throw (SPDT)
what material would you drill with a standard high speed steel drill bit
sheet metal
what material should you never drill with a standard high-speed steel drill bit
masonry
what migh you use to cut flexible metal conduit or liguidtight flex
a hacksaw
what sesimic zones are in CA
3&4
what is the min heigh if a guardrail
42 inches
how do you tell the difference between 568A cables and 568B
the pairs of wires are arranged differently
Conductor length and conductor size are both proportionally related to
resistance
what type of low voltage cable is required for use in a ceiling used for air-handling
plenum-rated cable
what are the general wiring requirements for a 70-volt background-music sound system
one pair of No 22 AWG
what does LAN stand for
Local Area Network
in a local antenna system, everthing after channel 14 and up is called
UHF
when do yo use singlemode fiber
Long distance
how do you test a short
ohmmeter
what is the most common size of fiber optic cable
62.5/125
what type of light pulses travel in multimode fiber optic cables
both high and low order
what type of light pules travel in singlemode fiber optic cables
low order only
how do you first test fiber
HeNe or LED laser
which is the most common type of cable for Data
CAT 5
which connector is the most commonly used for data processing
RJ45
how many wires does a typical 66-block hold
100
two techs are installing a data cable on one end. You connect the tracer at the office and the other at the block, but you do not get a signal. What should you conclude
you used the wrong cable
how do you measure the lenght of fiber on a spool
OTDR
which type of ladder should be used inside a buiding
wooden ladder
how far must the side rails of ladders exend above a landing
36 inches
what section of the NEC covers optical fiber
770
which of the following standards covers fire alarms
NFPA 72
what is the min diameter threaded rod you can use to suspend cable trays
3/8
what color are 568SC connectors and adapters for multimode fiber
beige
what color are 568SC connectors and adapter for singlemode fiber
blue
what tool is used to terminate 25-pair Amphenol plug
butterfly tool
what is the name of the outer covering for fiber optic cables
jacket
how many quarter bends are allowed in a single run of conduit
4
what do ladder color codes indicate
the maximun load
bridge clips are use
to bridge two sides of a parallel-connected 66m150 block
