Rural Electrification Flashcards
For motors with a marked service factor not less than 1.15, the multiplying factor to be used in determining for size of overload protection shall be ____.
a. 110 % c. 120 %
b. 115 % d. 125 %
d. 125 %
For a motor starter to be in sight of the controlled motor, it must NOT be more than ___ meters away.
a. 20 c. 25
b. 10 d. 15
d. 15
Flexible metallic tubing smaller than
___ electrical trade size shall NOT be used in wiring.
a. 20 mm c. 12 mm
b. 15 mm d. 32 mm
b. 15 mm
Consist of a group of wire twisted to form a metallic string.
a. Duplex wire c. solid wire
b. loomex wire d. stranded wire
d. stranded wire
Transformers that are installed in unsupervised locations and rated over 600 V are protected by fuses on the primary side and cannot exceed ____ percent of the primary full load current.
a. 150 c. 200
b. 300 d. 250
b. 300
Ratio of the maximum demand of a system or part of a system to the total connected load of a system or
the part of the system under consideration.
a. power factor
b. utilization factor
c. capacity factor
d. demand factor
d. demand factor
Type NM (non-metallic sheathed cable) shall be permitted for ____ work in normally dry locations.
a. exposed c. both a and b
b. concealed d. neither a nor b
c. both a and b
Conductors used only for grounding shall be _____.
a. green, green with yellow stripes, or yellow
b. green, yellow with green stripes, or bare
c. green, green with yellow stripes, or bare
d. green, yellow, or bare
c. green, green with yellow stripes, or bare
The lowest standard size of disconnect
is ____.
a. 20 A c. 30 A
b. 60 A d. 15 A
c. 30 A
Branch circuit conductors supplying a single motor shall have an ampacity NOT less than ____ percent of the motor full load current rating.
a. 115 c. 120
b. 125 d. 130
b. 125
Where the overload relay selected using the factor 125 % is not sufficient to start the motor or carry the load, the multiplying factor shall be increased but shall NOT exceed ____ percent.
a. 130 c. 140
b. 150 d. 160
c. 140
An exposed wiring support system using a messenger wire to support insulated conductors.
a. Metal clad cable wiring
b. Concealed knob and tube wiring
c. Messenger cable wiring
d. Messenger supported wiring
d. Messenger supported wiring
In replacing a busted fuse, which of the following is important?
a. same size and type
b. same type but different rating
c. same size but different rating
d. different size and type
a. same size and type
Which of the following wires has 75 ohm impedance?
a. Foam-filled twin lead
b. Flat twin lead
c. Coaxial
d. none of these
c. Coaxial
Consists of three or more flat copper conductor placed edge to edge separated and enclosed within an insulating assembly.
a. Armored cable
b. Sheathed cable
c. Flat cable assemblies
d. Flat conductor cable
d. Flat conductor cable
Rigid metal conduit shall be shipped in standard lengths of ___.
a. 3,000 mm c. 6,000 mm
b. 4,000 mm d. 5,000 mm
a. 3,000 mm
The term given to an insulated stranded wire.
a. Durability c. Cord
b. Pendant d. Receptacle
c. Cord
In which method of starting a motor is the starting current a minimum?
a. star-delta
b. direct on line
c. resistance starter
d. autotransformer
a. star-delta
Which of the following sizes of fuse is NOT standard?
a. 80 A c. 60 A
b. 125 A d. 75 A
d. 75 A
The smallest electrical trade size of
intermediate metal conduit.
a. 15 mm c. 20 mm
b. 12 mm d. 25 mm
a. 15 mm
The Philippine Electrical Code (PEC) is intended for ____ application by
government bodies exercising legal
jurisdiction over electrical installation.
a. advisory c. mandatory
b. optional d. all of these
c. mandatory
Before starting any installation work, alteration, repair or extension on any electrical system, what type of permit is needed?
a. Building permit
b. Electrical permit
c. Working permit
d. Mayor’s permit
b. Electrical permit
This type of cable is a fabricated assembly of insulated conductors enclosed in a flexible metal sheath.
a. Ground wire
b. Medium voltage cable
c. Messenger Wire
d. Armored cable
d. Armored cable
Which of the following electrical
conductor has the highest resistance?
a. 3.5 mm2
b. 2.0 mm2
c. 5.5 mm2
d. 20 mm2
b. 2.0 mm2
Electrical equipment may be best mounted on a concrete wall by using one of the following. Which
one is this?
a. wooden plug c. expansion bolt
b. load plug d. plastic plug
c. expansion bolt
The following copper conductors have the same cross-sectional
area but are made up of different number of strands. Which one has
the least resistance to AC current?
a. 19-strand conductor
b. 7-strand conductor
c. single solid conductor
d. 37-strand conductor
c. single solid conductor
Operation at substantially constant load for an indefinitely long time.
a. Periodic duty
b. Intermittent duty
c. Continuous duty
d. Short time duty
c. Continuous duty
In rigid metal conduit wiring, conduits shall be supported at least every
a. 2,500 mm c. 3,500 mm
b. 3,000 mm d. 2,000 mm
b. 3,000 mm
Auxiliary gutter shall not contain more than _____ current carrying conductors at any cross section.
a. 36 c. 30
b. 32 d. 24
c. 30
A machine that converts mechanical energy to electrical energy.
a. generator
b. motor
c. transformer
d. capacitor
a. generator
What type of electrical conductors has a trade name “moisture resistant thermoplastic” ?
a. TW c. THHN
b. THW d. All of these
a. TW
Liquidtight flexible nonmetallic conduit shall NOT be used where the voltage of the contained conductors is in excess of _____.
a. 600 V c. 250 V
b. 300 V d. 1000 V
a. 600 V
A point in a wiring system at which current is taken to be used in some equipment.
a. Grounded
b. Conductor
c. Service entrance
d. Outlet
d. Outlet
In concealed knob and tube wiring, the clearance to be maintained between conductor is
_____.
a. 55 mm c. 76 mm
b. 45 mm d. 50 mm
c. 76 mm
Operation of equipment in excess of normal full load rating or of a conductor in excess of rated ampacity.
a. Overload c. Overcurrent
b. Overvoltage d. Surge
a. Overload
When circuit breakers are installed in enclosed switchboards, they are derated to a certain percentage. What is this percentage?
a. 60 % c. 70%
b. 80% d. 50%
b. 80%
A short length of conductor used to make a connection between terminals or around a break in a
circuit.
a. jumper
b. guy
c. bonding conductor
d. tie wire
a. jumper
A gas circuit breaker is using a gas called SF6 as its interrupting medium. What does SF6 stands for?
a. sulfur fluoride
b. sulfur ferrite
c. sulfur hexafluoride
d. none of these
c. sulfur hexafluoride
A conductor having no covering or electrical insulation.
a. bare conductor
b. concealed conductor
c. encased conductor
d. exposed conductor
a. bare conductor
Fixture wire shall NOT be smaller than _____.
a. 1.25 mm2
b. 2.0 mm2
c. 0.5 mm2
d. 0.75 mm2
d. 0.75 mm2
All circuit conductors between the service equipment or the generator switchboard of an isolated plant, and the final branch circuit
overcurrent device.
a. overcurrent protection
b. branch circuit conductors
c. feeder
d. service entrance
c. feeder
What is the temperature rating of THW insulation?
a. 60 o C c. 75 o C
b. 90 o C d. 110 o C
c. 75 o C