Closed Book 3 Flashcards
To control a ceiling light from five different locations it requires which of the following?
A) four 3way switches and one 4way switch
B) three 4way switches and two 3way switches
C) three 3way switches and two 4way switches
D) four 4way switches and one 3way switch
three 4way switches and two 3way switches
The advantage of AC over DC includes which of the following?
A) better speed control
B) lower resistance at higher current
C) ease of voltage variation
D) impedance is greater
ease of voltage variation
Which of the following is considered the best electrical conductor?
A) iron wire
B) copper wire
C) aluminum wire
D) tin wire
copper wire
The liquid in a battery is called the _____.
A) askarel
B) festoon
C) hermetic
D) electrolyte
electrolyte
A color code is used in multiple-conductor cables. For a 3- conductor cable, the colors would be _____.
A) one black, one red, one white
B) two black one red
C) one white, one black and one blue
D) two red one black
one black, one red, one white
Explanatory material in the code is characterized by _____.
A) the word “shall”
B) FPN
C) the word “may”
D) the word “could”
FPN - informational note 90.5(C)
The identified grounded conductor of a lighting circuit is always connected to the screw of a light socket to _____.
A) reduce the possibility of accidental shock
B) ground the light fixture
C) improve the efficiency of the lamp
D) provide the easiest path to connect the wire
reduce the possibility of accidental shock
A _____ box may be weatherproof.
A) watertight
B) rainproof
C) raintight
D) all of these
all of these
The code requires that all AC phase conductors where used, the neutral and all equipment grounding conductors be grouped together when using metal enclosures or raceways. The principal reason for this is _____.
A) currents would circulate through individual raceways
B) less expensive to install a single raceway
C) less labor hours for pulling wires in a single raceway
D) conductors are easier to pull in a single raceway
currents would circulate through individual raceways
Installing more than three current carrying conductors in the same conduit requires _____.
A) a larger conduit
B) high heat rated conductors
C) derating of ampacity
D) continuous loading
derating of ampacity
A ____ helps prevent arcing in movable contacts
A) spring
B) condenser
C) resistor
D) hydrometer
condenser
The _____ circuit is the portion of the wiring system prior to final overcurrent protective device protecting the circuit.
A) service
B) feeder
C) power
D) branch
feeder
When tightening a screw on a terminal, the end of the conductor should wrap around the screw in the same direction that you are turning the screw so that _____.
A) when you pull on the conductor it will tighten
B) the screw will not become loose
C) the conductor will act as a locking nut
D) the conductor will not turn off
the conductor will not turn off
Determining a positive wire on a single-phase circuit is _____.
A) possible with a wattmeter
B) possible with a voltmeter
C) possible with an ammeter
D) an impossibility
an impossibility
A _____ is used for testing specific gravity.
A) thermocouple
B) megger
C) hydrometer
D) galvanometer
hydrometer
An autotranformer differs from other types of transformers in that _____.
A) its primary winding is always larger than its secondary winding
B) it can be used only in automobiles
C) its primary and secondary windings are common to each other
D) it must be wound with heavier wire
its primary and secondary windings are common to each other
In residential buildings, small appliance loads should have two or more _____.
A) 15 amp branch circuits
B) 20 amp branch circuits
C) 40 amp branch circuits
D) 50 amp branch circuits
20 amp branch circuits
If the end of a cartridge fuse becomes warmer than normal, you should _____.
A) tighten the fuse clip
B) lower the voltage on the circuit
C) notify the utility company
D) change the fuse
tighten the fuse clip
Which of the following is the poorest conductor of electricity?
A) mercury
B) aluminum
C) carbon
D) silver
carbon
The primary winding of a loaded step-down xfer has _____ compared to the secondary winding.
A)
B)
C)
D)
Copper is used for the tip of a soldering iron because _____.
A) copper will not melt
B) copper is a very good conductor of heat
C) solder will not stick to other alloys
D) copper is less expensive
copper is a very good conductor of heat
The sum of the voltage drop around a circuit is equal to the source voltage is _____.
A) kirchoffs law
B) ohms law
C) nevins theory
D) faradays law
kirchoffs law
Piezoelectric is caused by crystals or binding _____.
A) chemical
B) battery
C) pressure
D) heat
pressure
Heavy-duty lampholders include _____.
A) admedium lampholders rated at 660 watts
B) lampholders used on circuits larger than 20 amperes
C) lampholders rated at not less than 750 watts
D) all of the above
all of the above
The reason for installing electrical conductors in a conduit is _____.
A) to provide a ground
B) to increase the ampacity of the conductors
C) to protect the conductors from damage
D) to avoid derating for continuous loading of conductors
to protect the conductors from damage
Discoloring of one end of a fuse indicates _____.
A) increased current
B) excessive voltage
C) low resistance
D) poor contact
poor contact
Wing nuts are useful on equipment where _____.
A) cotter pins are used
B) the nuts must be removed frequently
C) a wrench cannot be used
D) screws cannot be used
the nuts must be removed frequently
When resistors are connected in series, the total resistance is _____.
A) the sum of the individual resistances
B) the equivalent of the smallest resistance value
C) the equivalent of the largest resistance value
D) less than the value of the smallest resistance
the sum of the individual resistances
If a 120 volt incandescent olight bulb is operating at a voltage of 125 volts, the result will be_____.
A) it may be enough to blow a fuse
B) the bulb won’t be as bright
C) shorter life of the bulb
D) the wattage will be less than rated
shorter life of the bulb
Laminations are used in transformers to prevent _____.
A) copper loss
B) weight
C) eddy current losses
D) counter EMF
eddy current losses
The code requires which of the following colors for the equipment grounding conductor?
A) white or gray
B) green or green with yellow stripes
C) yellow
D) blue with yellow stripes
green or green with yellow stripes
Sometimes mercury toggle switches are used in place of a regular toggle switch because they _____.
A) are easier to connect
B) do not wear out as quickly
C) are less expensive
D) they glow in the dark
do not wear out as quickly
The assigned color for the high-leg conductor of a three-phase, 4-wire delta secondary is _____.
A) red
B) black
C) blue
D) orange
Orange
The code rule for maximum 90 degree bends in a conduit between boxes is four, the most likely reason for the total 360 degree limitations is _____.
A) it is unsafe
B) it makes pulling the conductors through the conduit too difficult
C) you can damage galvanized coating on the conduit
D) too many bends require extra wire to be pulled
it makes pulling the conductors through the conduit too difficult
The correct word to define wiring which is not concealed is _____.
A) open
B) uncovered
C) exposed
D) bare
exposed
A solenoid is a _____.
A) relay
B) permanent magnet
C) dynamo
D) electromagnet
electromagnet
An electrician should always consider the circuit to be “hot” unless he definitely knows otherwise. The main reason is to avoid _____.
A) personal injury
B) having to find the panel
C) saving time
D) shutting off the wrong circuit
Personal injury
The best thing to cut PVC conduit within a tight area is _____.
A) a short hacksaw
B) a nylon string
C) a knife
D) a pipe cutter
a nylon string
If a live conductor is contacted accidentally, the severity of the electrical shock is determined primarily by _____.
A) the size of the conductor
B) whether the current is DC or AC
C) the current in the conductor
D) the contact resistance
the contact resistance
Ohm’s law is _____.
A) an equation for determining power
B) the relationship between voltage, current and power
C) the relationship between voltage, current and resistance
D) a measurement of wattage losses
the relationship between voltage, current and resistance
What is the normal taper on a standard conduit thread-cutting die?
A) 1/2” per foot
B) 1/4” per foot
C) 3/8” per foot
D) 3/4” per foot
3/4” per foot
In an AC circuit the ratio of the power in watts to the total volt-amps is called the _____.
A) demand factor
B) power factor
C) turns-ratio
D) diversity factor
power factor
A continuous load is where the maximum current is expected to continue for ____ hours or more
A) five
B) two
C) three
D) four
three
Which of the following is probably open when you test Phase A and Phase B and get a low voltage reading, test Phase B and C get a normal reading and test Phase A and C get a low voltage reading?
A) Phase A
B) Phase B
C) Phase C
D) none of these
Phase A
A ladder which is painted is a safety hazard mainly because the paint _____.
A) may conceal weak spots in the rails or rungs
B) is slippery after drying
C) causes the wood to crack more quickly
D) peels and the sharp edges of the paint may cut the hands
may conceal weak spots in the rungs or rails
The chemical used as the agent in fire extinguishers to fight electrical fires is _____.
A) CO2
B) KoH
C) H20
D) Lo6
CO2
A location classified as _____ may be temporarily subject to dampness and wetness
A) dry
B) damp
C) moist
D) wet
dry
The average dry cell battery gives an approximate voltage of _____.
A) 1.5
B) 1.2
C) 1.7
D) 2.0
1.5
The _____ circuit is that portion of a wiring system beyond the final overcurrent protection.
A) lighting
B) feeder
C) signal
D) branch
Branch
Which of the following will NOT affect the resistance of a circuit?
A) length of the conductor
B) diameter of the conductor
C) insulation of the conductor
D) temperature
insulation of the conductor
