Electrical Exam
In all cases where there are live parts normally exposed on the front of such switchboards or motor control centers, the working space in front of such equipment shall not be less than:
3'
What is the minimum working clearance from the front of an enclosed 277V/480V panel when there are no other live or ungrounded parts on the other side of the working space (Condition 1)?
3'
Electrical metallic tubing is permitted to be used in sizes up to:
4"
The minimum burial depth for a PCV conduit under a 4" concrete slab is
4"
The derating factor for the 22 conductors in a raceway serving loads without diversity is ( ) %?
45
What is the line to the neutral voltage on a low-voltage WYE system is ( ) V.
480V
The minimum bending space for two 250 kcmil conductors in a gutter is
6
Rigid metal conduit must be buried at least ( ) in locations not otherwise specified.
6"
Two or more ground rods shall not be less than ( ) apart.
6'
A class "A" annuciating zone has 7 speakers. A fire caused break in the wires between speak #3 and #4. How many speakers will still work?
7
The output rating of one horsepower motor is?
746 watts
A total of ( ) #12 conductors are allowed in 4" x 1 and 1/4" square box.
8
What is the take up allowance for a 1" emt bender
8"
The total load on any over current device located in panel board shall not exceed rating where in normal operation the load will continue for three hours or more.
80%
A bonding jumper is:
A reliable conductor to assure the required electrical conductivity between metal parts required to be electrically connected
3-way switching does not use the following conductor;
Grounded
"Thermally protected" appearing on the nameplate of a motor indicates that the motor is provided with a:
Heat sensing element
You are installed a used three-phase wye connected motor and find leads 4 and 7 connected together. The motor was last used on:
High Voltage operation
OHMS law can be shown as:
I=E/R ; R=E/I ; E=IxR
What does a "NEMRA 3R enclosure" indicate?
The electrical application is rain tight
The voltage drop in a line can be decreased by:
Increasing wire size
If the fuse becomes hot under normal load, a probable cause is
Insufficient pressure at the fuse clips
The neutral conductor;
Is always the "white or gray" grounded conductor
The resistance of a circuit may vary due to
Loose connection
The larger the conductor, the
Lower the resistance
You need to size a pull box in a run of 3" conduit with 4-4/0 THW conductors. The conductors will be going straight through the pull box. What is the minimum length the pull box can be?
24"
A load is considered to be continuous if expected to continue for;
3 Hrs
Conductors ( ) and larger shall be stranded when installed in a raceway.
#8
The underground conductor can be identified by the color (s)
(None of the colors listed- white or gray, green or bare, pink flamingo)
What is the smallest conductor that can be used to parallel feed a 277/480 V 60 HZ panel?
1/0
A piece of electrical equipment has no AIC rating, what rating should be applied based on the NEC?
10
One receptacle installed on an individual branch circuit shall have a rating not less than % of the rating of the branch circuit
100
How many #12 conductors does the code allow in a 4" x 4'' x 2 and 1/8" deep J-Box?
13
The Primary purpose for grounding a raceway is to prevent the raceway from becoming:
Accidentally or unintentionally energized
What instrument is used to measure current?
Ammeter
The ( ) circuit is the portion of a circuit after the final over current protective device protecting the circuit to an outlet(s).
Branch
In a 277V/480V 3-phase 4 wire panel, what color would circuit #19 be?
Brown
Which of the following would have the least amount of resistance?
Conductor
( ) or larger determine if a bushing is required on a raceway.
Conductors #4
In a series circuit, ( ) is common:
Current
The common fuse relies on the electrical principle that:
Current flow develops heat
Installing more than three current carrying conductors in the same conduit requires
Derating of ampacity
Always connect an ammeter in parallel with a load.
False
Derating factors must be applied to nipples that do not exceed 24 inches in length
False
Start buttons must be connected in series to energize the coil of a magnetic starter.
False
Stop buttons must be connected in parallel to stop a motor controlled by a magnetic starter.
False
A motor works based on the principle of
Magnetism
Where would you find a neutral bus?
Main service panel
The assigned color for the high-leg conductor of a three phase, 4 wire delta secondary is
Orange
Multiple start buttons in a motor control circuit are connected in:
Parallel
The high leg of a delta secondary shall be connected to
Phase B
To convert AC to DC, you will use a:
Rectifier
Electrical contacts are opened or closed when the electrical current engergizes the coils of the device called a:
Relay
If the voltage is doubled the ampacity of a conductor:
Remains the same
To reverse the rotation of a 3-phase motor you would
Reverse any two of the three leads
Enclosed knife switches that require the switch to be opened before the housing door can be opened are called ( ) switches.
Safety
Which winding down of a step-down transformer will carry more current?
Secondary
In which fashion is a stop switch wired in a motor circuit?
Series
The stop button is connected in ( ) for a motor control circuit.
Series
The service grounding electrode conductor is sized by the:
Size of the largest ungrounded service conductor
The letters "DPDT" are used to identify a type of
Switch
The definition of ambient temperature is:
The temperature of the area around the conductor
A ( ) over current device is not designated to interrupt short-circuit current.
Thermal cutout
To control a ceiling light from five different locations, it requires which of the following:
Three 4-way switches and two 3-way switches
A megger can be used to test the insulation breakdown for copper conductor.
True
A lamp can be controlled from three different points by ( ) switches.
Two 3-way and one 4-way
What is meant by traveler wires?
Two wires between 3-way switches
Your foreman asks you to measure the insulation resistance of some conductors. To do this, you would:
Use a megger
The voltage lost across a portion of a circuit is called;
Voltage drop
The measurement of the electromotive force of a circuit is accomplished using a
Voltmeter
The neutral conductor in a 120 V, single phase, two-wire grounded system must be:
White or neutral