C7 test deck Flashcards
Power Factor is
The ratio of true power to apparent
WATTS equals
volts X amps
If watts =volts x amps, amps equal:
watts dvided volts
a device with a resitance of 20 ohms is connected to a 120 v circuit. acording to Ohm’s law, how many amps will it draw
6 amps
a device draws 3 amps at 120 v. according to Ohm’s law, what is its resistance
40 ohms
a applicance has a resistance of 24 ohms and draws 0.5 amp. According to ohm’s law, what voltage should be supplied
12 volts
a device consumes 2400 watts of power at 120 volts. accodring to Wastts law, will at 15 amp circuit be sufficent for the device.
no it will draw 20 amps
a customer has a living room circuit with the following devices: one 60 wat device, five 100 watt devices, and a six 90 watt devices. The customer daughter wants to add a 500 watt stero system rated at 800 watts output- to the circuit. What is the total watt potentially conusmed if the stero is added
1600 watts
an electrician is checking a 12-volt circuit that appears to be overloaded. A meter cannot be placed on the circuit directly, so the total load must be calculated. The circuit has an overcurrent device set 15 amps. the circuit had a total of five 50-watt devices. Is the Circuit overloaded
Yes the circuit dwas 20.8 amps.
One megahertz refers to how many cycles per second
one million
a device consumes 2400 watts of power at 120 volts. According to Watts law, will a 15 amp circuit be sufficient for the devices
no it will draw 20 amps
The abbrevation MHZ stand for
megahertz
one gigahertz refers to how many cycles per second
one billion
the abbrevation GHz stands for
gigahertz
what type of drill bit is most suitable for masonary
carbide
you are drilling into cocrete with a carbide bit. After a while , dust stops coming out of the hole even though you are apllying pressure with a sharp bit. You conclude that you have probalby run into into piece of rock. You should
shift to a star drill
the main reason copper is prefteeed to aluminum for wiring is that copper
has less resitance that alumninum
what is the purpose of a maddrel
to clear or check conduit before pulling wire
compression connectors and lugs are attached to conductors
by crimmping with a special tool
what is used to reduce voltage from 120 V to 24 V
step-down transformer
Conduit is specified by
nominal interior diameter
Promary and secondary windings refer to
transformer
what type of cable may be buried underground
Type UF
Which of the following is designed to protect the user from shock
GFCI
Power tools and electrical equipment must be grounded. Double- insultate power tools
do not have to be grounded
what do the follwong tools have in common: drills, tappers, fasteer drivers, grinders, disc amd belt sanders, saber saws, circular saws and chain saws
they require a constant contact on off switch
A thermostat should be mounted approximatel from the floor
5 feet
which of the follwoing statmets is not correct concering the installation of a thermasat
install it near ductwork
according to the NEC, the min cover for the direct buried cables or conductors is
24”
according to the NEC the min cover for the rigid nonmetalic conduit is
18”
according to the NEC the max distance between supports in straight runs of EMT (electical metalic tubing) is:
10 feet
according to the NEC nonmetallic sheathed cable ( type NM or NMC must be secured at intervals no greater than
4- 1.2 ft
according to the NEC, nonmetallic sheather cable (type NM or NMC) must be secured within blank of evey cabinet, box or fitting
12 inches
while operating which tool is most important to wear gloves
cutters
according to the NEC, the ampacity form generator terminals to the first overcurrent device must be at least blank of the nameplate current rating of the generator
115%
in a generator where wires pass thougha n opening in an enclosure, conduit box, or barrier, use a blank to protect the conductor for sharp edges
bushing
the grounding conductor must be made of
copper, aluminumn, copper-clad aluminumn
best to cut EMT tubung
pipe cutter
hackswas to cut EMT, it should have a blad nor carser than
24 teeth per inch
Reaming a cut piect of EMT should take place
immediatly after cutting it
transformers rated at 600 volts must be protected by an overcurrent device on the primary side rated or set at no more than______rated primary current of the transformer
125%
single pole siwth with a test ligh. First you put the swithch in the off postion. Than , with one probe on the ground, you altenately place the other probe on each of the two terminals. It lighs both times an you coconclude the switch is working. you proceeeded
incorrectly. The swithc should hav been in the ON postion for testing.
voltage reading with a test instrument are alwas taken
across the circuit
the insrument used to test resitance, in megohms, to the flow of current thoiugh and/or over the surface of insulation opf electical equipmentis called
Megger
which device instument measures power
Wattmeter
volmeters are connected
across the load of a closed circuit
Ammeters are connected
in series in a closed circuit
Ohmmeters are connected
across the load of an open circuit
Wattmeters are connected
accoss the load in a closed circuit an in series in a closed circuit
to measure resistance
Ohnmeter
to measure current
ammeter
when measuing low voltage circuit in a system the is not working propperly. You insert the probes of a test light into the two slots of a 120 V recepticle and the test light comes on. You would conclude that:
the circuit wiring is defective
the main symtoms of shock
pale skin, swaty skin, fast pulse
the ground within______of buildings under construction must be kept free from irregularities what it is practicable
6 feet
step ladders may be no taller than
20 feet
cleat laddes may be no taller than
30 feet
extension ladder may be no taller than
44 feet
section of extenion ladders must ovelap by at lead blank of the working lenght
10%
before you a dig a tench or excavation, detemin the location of undergorund utilites an notify the owner at least blank in adance
48 hours
when digging a trench the best way to ge info on undergorun utilites is to
call the local utility company and call th undegoun servie alert
tailgate saftey meeting of supervisors with empoyees are required at l
least every 10 days
a dosh permit is required for
constucitionof trnech over 5 ft demo scafolding
MSDS
Materail safety data sheet
an employer whose empolyees use a substance listed in the list of hazardous substances must provide
an MSDS and training
how should you treat a burn on a job site
lose bandages only
