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