Review Flashcards
What type of wire, when run in free air, can carry the most current? A) RA-90 Aluminum B) RA-90 Copper C) Steel D) Bare Copper
Bare Copper
Book 1
What is the size of a bare conductor having occupied area of 405 mm^2 A) 450 KCM B) 500 KCM C) 600 KCM D) 800KCM
600 KCM
Book 1
What minimum length of pull box is required for a straight through pull when there is 53 trade size conduit and 78 trade size conduit entering the top of the box and leaving the bottom of the box and all the conductors are #3 AWG or larger?
A) 12”
B) 16”
C) 18”
D) 24”
24”
Book 1
What is the maximum number of No. 8 TW wires that may be installed in a 6x6x4 pull box?
A) 36
B) 60
C) 53
D) 52
52
Book 1
What wiring method do you use to wire a motor control center (MCC), the feeders are from the bottom encased in concrete?
A) AC90
B) PVC conduit with a bond
C) USEI
D) EMT
PVC conduit with a bond
Book 1
Which secondary terminal should be grounded?
A) H1
B) H0
C) X0
D) X1
X0
What is the minimum radius bend permitted in a 35 mm ridgid aluminum conduit?
A) 102mm
B) 184mm
C) 210mm
D) 241mm
184
What is the maximum voltage that can be marked as “Extra-low voltage”?
A) 30 volts
B) 25 volts
C) 120 volts
D) 48 volts
30 volts
Where may NMD-90 copper cable be used?
A) in concrete
B) wet locations
C) damp locations
D) under carpet
Damp locations
What is the maximum distance from a switchbox that the first clamp may be fastened to non-metallic sheathed cable?
A) 150mm
B) 100mm
C) 200mm
D) 300mm
300 mm
The proper method of cutting the armoured covering off armoured cable is:
A) at 90 degree to the cable with a hacksaw
B) diagonally across the weave with a hacksaw
C) by breaking the weave and then using diagonal pliers
D) by pulling a cable stripper along the cable
Diagonally across the weave with a hacksaw
Anti-short bushings are used for protection conductors in:
A) EMT
B) NMS
C) A/S
D) AC
AC
Which of the following type/types of cable is not suitable fkr dirext burial?
A) RA90 cable
B) TWU cable
C) AC cable
D) M1 cable
AC cable
2 loads in parallel
R1= 40 ohms
E= 100V
A) 64 ohms
B) 16 ohms
C) 40 ohms
D) 60 ohms
60 ohms
What is the correction factor for calculating the amperage rafing of TW wite when there are 8 current carrying eires in one conduit?
A) 70%
B) 80%
C) 90%
D) 125%
70%
The capacitor in a single phase motor does not provide for
A) correcting the power factor
B) limiting the starting current
C) a leading current in the start winding
D) a lagging current in the run winding
D) a lagging current in the run winding
Book 1
A step down transformer having a turn ratio of 10-1 and 110 volts across the primary will have a secondary voltage of
A) 1100 volts
B) 11 volts
C) 1.1 volts
D) 5.5 volts
B) 11 volts
Book 1
A device for measuring the diameter of a motor shafts is
A) micrometer
B) hydrometer
C) megometer
D) microhmmeter
A) micrometer
The overload rating for a two-horse power squirrel cage motor should be _____ percent of the full load current of the motor when the service factor is 1.15
A) 125%
B) 150%
C) 115%
D) 300%
A) 125%
Book 1
The maximum voltage allowed between conductors in a surface metal raceway is
A) 600v
B) 250v
C) 300v
D) 125v
C) 300v
Book 1
If an underfloor cell system is not constructed of continuous metal the most practical procedure for providing bonding would be to
A) use the neutral as a bonding conductor
B) individually bond each section of metal together
C) use the metal of cell as bond
D) pull in bonding conductors with the branch circuits
D) pull in bonding conductors with the branch circuits 12-1814(1)
Book 1
What is the maximum cross-sectional area of an underfloor duct filled by conductors and their insulation
A) 50%
B) 40%
C) 20%
D) 75%
B) 40% 12-1714
Book 1
If a could of a 5 ohm resistance is connected in series with two coils, 9 ohm and 18 ohm in parallel, the combined resistance in ohms is
A) 51.6 ohms
B) 5.17 ohms
C) 11 ohms
D) 37 ohms
C) 11 ohms
The power taken by a single phase motor is 800 watts, current is 9 amps, and 120 line voltage. The motor is operating at a power factor of
A) 75%
B) 80%
C) 95%
D) unity
A) 75%. Pf=w/va 800w/(9Ax120v)
What is used to prevent scaffolding from toppling due to high centre of gravity
A) locking wheels
B) cross braces
C) toe planks
D) outriggers
D) outriggers
A point in the wiring system where current is taken to supply utilization equipment is called A) outlet B) switch box C) a pull box D) junction box
A) outlet. Section 0
A three phase supply may be obtained by using only two transformers if
A) a star connection is used
B) a delta connection is used
C) an open delta connection is used
D) a centre-tapped closed delta is used
C) an open delta connection is used Cec pocket book
Book 1
The speed of a two pole motor with 4% slip connected to a 60 cycle source is
A) 3456 rpm
B) 3600 rpm
C) 7200 rpm
D) 6912 rpm
A) 3456 rpm.
120x60/2 =3600 rpm with 4% slip
Book 1
Bare neutral service conductors can be used if the following condition is met
A) conductor is made of copper and direct buried
B) conductor is made of aluminum and run in EMT
C) conductor is made of aluminum and run in rigid PVC conduit underground
D) conductor is made of copper and installed in rigid metal conduit
D) conductor is made of copper and installed in rigid metal conduit
6-308
Book 1
When connecting a lug to an aluminum
Bus bar, which is satisfactory
A) flat washer
B) a locknut
C) lock washer
D) a conical spring washer
D) conical spring washer 12-118(5)
Book 1
A fibre optic cable has no signal at the receiving, what is the likely cause
A) cable kinked
B) voltage drop
C) light generator faulty
D) cable buried too deep
A) cable kinked
The maximum voltage drop on 600 volt branch circuit conductors is
A) 30v
B 18v
C) 7.2 v
D) 12v
D) 12v. 8-102(1a)
The functions of grease in the bearings of an electrical motor is to
A) protect the shaft of the motor
B) reduce heat from mechanical friction
C) allow the motor to run smoother
D) protect the windings from arching
B) reduce heat from mechanical friction
Line 1, 120v 3A
Line 2, 120v 8A
Share neutral, and it breaks. What is the new voltage of line 1
A) 120v
B) 240v
C) 175v
D) 65v
C) 175v R1=120v/3A=40ohm R2=120v/8A=15ohm Rt=40+15=55ohm It=240/55=4.36a V1=4.36x40=175ohm V2=4.36x15=65ohm
Do logic symbol stuff
What minimum depth is required when burying underground DC wiring for catholic protection
A) 600mm
B) 450mm
C) 300mm
D) 200mm
D) 200mm
80-002(1b)