Jr. Closed Book Exam
Thermally protected, appearing on the nameplate of a motor indicates that the motor is provided with a ____________.
Heat sensing element
When's 60 watt bulb is connected in series with a 500 watt room heater and the bulb is replaced with a 25 watt bulb the _______.
Heater output will decrease
The presence of current is only made known by the effect it produces. Three important effects are ________.
Heating, magnetic and electric shock
An open coil can be detected by a ________ reading.
High resistance
DC series motors are used in applications where ______ is required.
High starting torque
The side of a transformer with more turns is the ________side.
High voltage
The primary winding of a loaded step-down transformer has _____ compared to the secondary winding.
Higher voltage and lower current
The _______ is wha limits the size of induction motor that can be started across the line.
Horsepower rating
The efficiency of a motor is a measure of ________.
How well it converts electrical energy into mechanical energy
A _____ is used for testing specific gravity
Hydrometer
The lagging effect between the magnetizing force applied and the flux density is _______.
Hysteresis
_______ has the highest electrical breakdown strength and longest life over all other materials used for insulation.
Impregnated paper- ( is a sheet with superior liquid-retaining and water-absorbing properties and is made from natural cotton Lenten and wooden pulp.
Conductor sizes are expressed ________.
In AWG or in circular mils
Listed or labeled equipment shall be installed, used, or both, in accordance with any instructions included ______.
In the listing or labeling, or with the equipment from the manufacturer
The least sufficient lightning source is the _________.
Incandescent
A high spot temperature in a corrode electrical connection is caused by a (an) ________.
Increase in the voltage drop across the connection
The inert gas present in an incandescent bulb is primarily intended to ________.
Increase lumen output
A/an _________ motor has no commutator
Induction
A low factor is commonly caused by ________.
Induction motors and fluorescent lights
An electrician in the industry would first check the ______ to correct a low power factor.
Inductive load
An open fuse has a resistance of _______.
Infinity
An open resistor when checked with an ohmmeter reads _______.
Infinity
A low power factor in an industrial plant is most likely caused by ______.
Insufficient resistive loads
The transformer oil used in a transformer provides_______.
Insulation and cooling
A/an ________ is a material with atoms in which the electrons tend to stay in their orbits.
Insulator
A negative charge ________.
Interacts with both positive and negative charges
A/an _______ is a device actuated by the operation of some devices with which it is directly associated, to govern succeeding operations of some or allied devices.
Interlock
A circuit breaker that has purposely introduced into it a delay in the tripping action and which delay decreases as the magnitude of the current increases is a _____ circuit breaker.
Inverse time
A good magnetic material is ______.
Iron
Galvanized conduit is made of _______.
Iron
The open circuit test on a transformer is a test for measuring its _______
Iron losses
Acid is not considered a good flux when soldering conductors because it _______.
Is corrosive
A stranded wire with the same AWG as a solid wire _______.
Is larger in total diameter
Not readily accessible to persons unless special means for access are used is _______.
Isolated
All wiring must be installed so that when completed _______.
It is free of shorts and unintentional grounds
The main reason that electrical appliances are connected in parallel rather than series is ________
It makes the operation of each appliance independent with each other
The energy in a battery cell depends mainly on __________.
It's physical size
An autotransformer differs from other types of transformers in that __________.
Its primary and secondary windings are common to each other
As compared with solid wire, stranded wire of the same gauge size is _____.
Larger in total diameter
Capacitance increase with _______.
Larger plate area and smaller distance between plates
The resistance of a wire is directly proportional to the ________ and inversely proportional to the cross-sectional area.
Length
The advantage of cutting a metal rigid conduit with a hacksaw rather than a pipe cutter is ________.
Less reaming is required
You should close a knife switch firmly and rapidly as there will be less ________.
Likelihood of arcing
A rigid conduit connecting to an outlet box should have ________.
Locknut on the outside and a bushing on the inside
_______ are used on conduits and are located inside and outside of the box.
Locknuts
The brightness of an incandescent lamp is rated in _______.
Lumens
The process by which a magnetic substance becomes a magnet when it is placed near a magnet is called _______.
Magnetic induction
At lagging loads, armature reaction in an alternator is ________.
Magnetizing
The effect of increasing the length of air-gapin an induction motor will be to increase the __________.
Magnetizing current
The connection between the grounded circuit conductor and the equipment grounding conductor at the service is called the _____ bonding jumper.
Main
Pigtails are used on brushes to ______
Make a good electrical connection
The most important reason for using a consulted-type fitting in preference to making a bend in a one inch conduit is to ________.
Make wire pulling easier
A ladder which is painted is a safety hazard mainly because the paint ________.
May conceal weak spots in the falls or rungs
When using compressed air to clean electrical equipment the air pressure should not exceed 50 pounds. The main reason is higher pressures _____.
May loosen insulating tape
It is as a safety measure, not to use water to extinguish electrical equipment fires. The main reason is that water _____.
May transmit shock to the user.
A Wheatstone bridge is used to measure _______ resistance..
Medium and high
A ______ lamp requires a cooling period prior to restarting.
Mercury
An ion
Might have either a positive or negative charge
Type TW conductor is a _____ type
Moisture resistance and thermoplastic
Parallel battery cell have the same voltage as one cell but have ________.
More current capacity
If the secondary voltage of a transformer is step-down, the primary will have _______.
More turns than the secondary
The National Electrical Code is sponsored by the _______.
National Fire Protection Association
Where conductors with an ampacity higher than the ampere rating or setting of the overcurrent device are used, the _____ shall determine the circuit rating.
Overcurrent device
A/an _______ is used to protect a motor for overcurrent due to an excessive load.
Overload
_______ raceways are not suitable to enclose conductors that are subject to physical damage.
PVC schedule 40
__________ has the lowest dielectric strength
Paper
A voltmeter is connected in _____ with the load.
Parallel
Receptacle in residential wiring are regularly connected in ________.
Parallel
The breakdown voltage of an insulation depends upon _______ value of AC voltage.
Peak
A device or equipment which is suspended from overhead either by means of a flexible cord carrying current, or otherwise is a _____.
Pendant
The ungrounded conductor can be identified by the color __________.
Pink flamingo
Wiring systems in wet locations should be __________.
Placed so a permanent air space separates them from the supporting surface
Insulated nonmetallic boxes are made of ______.
Polyvinyl chloride and babelite
Discoloring of one end of a fuse normally indicates ________.
Poor contact
An ammeter must always be connected in the circuit under test ________.
Positive to positive and negative to negative
The lubricant used to make pulling wires through a conduit easier is _______.
Powdered soapstone
In AC circuit, the ratio of kw/kva represent the _______ factor.
Power
In an AC circuit the ratio of the power in watts to the total volt-amp is called the ______.
Power factor
The instrument used to indicate phase relation between current and voltage is the _______.
Power factor meter
To convert DC to AC you will use a _______.
Power inverter, or inverter
Piezoelectric is caused by crystals or binding _______.
Pressure
Insulating materials have the function of _______.
Preventing a short circuit between conducting wires
A cell that can not be recharged is a __________.
Primary cell
When wrapping a splice with both rubber and friction tape, the main purpose of the friction tape is to ________.
Protect the rubber tape
A box with a blank cover which is inserted in one or more runs of raceways to facilitate pulling of the conductors is a _______.
Pull box
______ is the type letter for conductors that are moisture and heat resistant rubber.
RHW
Electrical power is a measure of ________.
Rate at which work is performed
As the power factor of a circuit is increased ________.
Reactive power is decreased
A wattmeter indicates ______.
Real power
The kilowatt-hour meter can be classified as a/an _____ instrument.
Recording
A (an) ______ changes AC to DC
Rectifier
To convert AC to DC you will use a _______.
Rectifier
Which of the following statements is incorrect?
Rectifiers change DC to AC
The identified grounded conductor of a lighting circuit is always connected to the screw of a light socket to _________.
Reduce the possibility of accidental shock
An advantage of a 240 volt system compared with a 120 volt system of the same wattage is _______.
Reduced voltage drop
An automatic device that operates at preset values is known as a ________.
Relay
Electrical contacts are opened or closed when the electrical current energizes the coils of a device called a _______.
Relay
A ______ is a certain type cartridge fuse that can be readily replaced.
Renewable fuse
The quantity of magnetism retained by a magnetic material after withdrawal of the magnetizing force is called ________.
Residual magnetism
Heat is a form of wasted electrical energy dissipated by ________.
Resistance
The Wheatstone bridge method is used for accurate measurements of ________.
Resistance
Which of the following would cause the most power to be dissipated in the form of heat?
Resistance
The most heat is created when current flows through which of the following?
Resistors cause mor heat
To change the rotation of a DC motor you would _______.
Reverse F1 and F2
The direction of rotation of a single-phase motor can be reversed by ________.
Reversing connections of starting winding
The flux commonly used for the soldering of electrical conductors is _______.
Rosin
A three-way switch is equivalent to a _________ switch.
SPDT
Enclosed knife switches that require the switch to be open before the housing door can be opened, are called ______ switches.
Safety
Which one of the following is not an insulator?
Salt water
An excellent diffuser surface is one that _______.
Scatters light uniformly in all directions
An electrical diagram showing the control components rearranged to simplify the tracing of the circuit is a ______ diagram.
Schematic
The ground conductor would connect to the _______ of a lamp holder.
Screw shell
If the primary of a transformer is 480 volts and secondary is 240/120v, the wire on the ______ is larger.
Secondary
Wound rotor motors are usually started with a _______.
Secondary resistance starter
A premises wiring system whose power is derived from a source such as a transformer that has no direct connection to the supply conductors originating in another system is a/an ______ system.
Separately derived
The generator which is best suited for electroplating power is a _________ generator.
Separately excited
The service conductors between the terminals of the service equipment and a point usually outside the building, clear of building walls. Where joined by tap or splice to the service drop is called the _______.
Service-entrance conductors
Mandatory rules of the Code are identified by the use of the word ________.
Shall
If a test lamp lights when placed in series with a condenser and a suitable source of DC , it is a good indication that the condenser is _____.
Short-ciruited
When a current leaves it's intended path and returns to the source bypassing the load the circuit is ________.
Shorted
When an ammeter is disconnected from an in-service current transformer, the secondary terminals of the current transformer must be ______.
Shorted
If a 120 volt incandescent light bulb is operating at a voltage of 125 volts, the result will be _______.
Shorter life of the bulb
Insulating safety grips on tools ________.
Should be used with other insulating equipment
A voltage or current that is reversed at regular intervals is called ______ voltage or current.
Sinusoidal
Where lighting outlets are installed in interior stairways, there shall be a wall switch at each floor level to control the lighting where the difference between floor levels is _____ steps or more.
Six
On a #4 drill bit, the #4 is determined by _________.
Size
When AC current is passing through a conductor, there is a tendency for the current to crowd near the surface of the conductor. This is known as the _______.
Skin effect
Where galvanized conduit is used, the main purpose of the galvanizing is to _______.
Slow down rust
Of the following, the best indication of the condition of the charge of a lead acid battery is the ________.
Specific gravity
The condition of a liquid electrolyte in a battery is measured in terms of its _______.
Specific gravity
A type of motor that will not operate on DC is the _______.
Squirrel cage
When cutting holes in masonry which of the following tools is most commonly used?
Star drill
The transferring of electrons from one material to another would be ______.
Static electricity
The "stator" of an AC generator is another name for the ______.
Stationary portion
Which of the following is not used to fasten equipment to concrete ?
Steel bushing
Artificial respiration after a severe electrical shock is necessary when the shock results in ______.
Stoppage of breathing
When applying rubber tape to an electrical splice, it would be necessary to ________.
Stretch the tape properly during the application
When thermal overload relays are used for the protection of polyphase induction motors, their primary purpose is to protect the motors in case of _____.
Sustained overload
A type of AC motor that runs at a constant speed and is used for such purposes as an electric clock motor is a _____ motor
Synchronous
The conductor with the highest insulation temperature rating is _______.
THHN
An instrument used to measure the speed of a motor or generator is a _______.
Tachometer
What type of fastener would you use to mount a box to a hollow tile wall?
Toggle bolts
Alternating current may be increased or decreased by means of a ________.
Transformer
When the term "10-32" in connection with machine screws commonly used in lighting work, the number 32 refers to ______.
Treads per inch
For screw shell devices with attached leads, the conductor attached to the screw shell shall be _____ in color.
White or gray
When the temperature of a copper wire is raised, the resistance _______.
Will increase
________ are sheet metal troughs with hinged or removable covers for housing and protecting conductors and cables which are laid in place after this object has been installed as a complete system.
Wireways
The location of a wall receptacle outlet in the bathroom of a dwelling shall be installed ________.
Within 36" of outside edge of basin ( bathroom sink )
If a single-phase induction motor runs slower than normal, the most likely cause or defect is _______.
Worn bearings
Is it permissible to install direct current and alternating current conductors in the same outlet box?
Yes, if insulated for the maximum voltage of any conductor
______ is the combined opposition to current by resistance and reactance.
Z
When a switch is closed it has a total resistance of________.
Zero
Galvanized conduit has a finish exterior and interior of ______.
Zinc
Brass is an alloy of ________.
Zinc and copper
The purpose of a clip clamp is to ________.
ensure good contact between the fuse terminals of cartridge fuses and the fuse clips
When working near acids storage batteries, extreme care should be taken to guard against sparks, essentially to avoid ________.
An explosion
Determining a positive wire on a single-phase circuit is _________.
An impossibility
What kind of instrument is an ammeter?
An indicating
Dielectric is another name for _______.
An insulator
Operation of equipment in excess of normal, full load rating or a conductor in excess of rated amps city is called ________.
An overload
The cross-sectional area of the bus bar is ________ square inch.
Area sq. Inch = h x w, 1/2(.5) x 1/4(.25) = .125
The rotating part of a DC motor is known as ________.
Armature
A generic term for a group of non-flammable synthetic chlorinated hydrocarbons used as electrical insulating media
Askarel - a synthetic electrically insulating liquid that is non combustible
Ona simple ohmmeter, the 0 ohms mark is located __________
At the far right
The smallest element of matter is the _________.
Atom
All matter, whether gas , solid, or a liquid, are composed of _________.
Atoms
______ is self-acting, operating by its own mechanism when actuated by some impersonal influence, as for example, a change in current strength, pressure, temperature, or mechanical configuration.
Automatic
Large squirrel cage induction motors are usually started at a voltage considerably lower than the line voltage to _______.
Avoid excessive starting current
An AC ammeter or voltmeter is calibrated to read RMS values; this means the meter is reading the _______ value.
Effective
The ____ value is considered as the most important value of a sine wave
Effective
A light bulb usually contains ________.
Either a vacuum or gas
Utilization equipment is equipment which utilizes _______ energy for mechanical, chemical, heating, lightning or similar purposes.
Electric
_______ an electrical device characterized by its capacity to store an electric charge, better known as the name _______.
Electrical condenser, Capacitor
________ can be generated.
Electrical energy
For maximum safety the magnetic contractors used for reversing the direction of rotation of a motor should be _______.
Electrically and mechanically interlocked
A tool used by a lineman to remove insulation from large cables is called ______.
Electrician's knife
The liquid in a battery is called the ______.
Electrolyte
A solenoid is a _______
Electromagnet
Electrical current is measured in terms of ________
Electrons passing a point per second
Copper -clad aluminum conductors have an ampacity _______
Equal to aluminum
A negative charged body has __________.
Excess of electrons
Raceways shall be provided with _____ to compensate for thermal expansion and contraction.
Expansion joints
A motor enclosure designed and constructed to contain sparks or flashes that may ignite surrounding gas or vapor is called _______.
Explosion proof
Explanatory material in the code is characterized by _______.
FPN
The ________ circuit is that portion of a wiring system prior to the final overcurrent protective device protecting the circuit.
Feeder
_______ lightning is a string of lights suspended between two points.
Festoon
To adjust the voltage generated by a constant speed DC generator, you would change the________.
Field current
If a 240V heater is used on 120V, the amount of heat produced will be _______.
Find the resistance, let's say the heater has a factor rating of 2000 watts, R=Esq./ watts, = 240Vsq./ 2000 watts = 28.8 ohm, watts = Esq./ohms = 120Vsq. / 28.8 = 500watts, 2000watts/500watts = 4 is also 1/4 as much
A commutator of a generator should be cleaned with which of the following?
Fine sandpaper
Opening around electrical penetrations through fire-resistance rated walls, partitions, floors or ceiling shall be _______.
Firestopped
An electrical symbol represented by a rectangle with a circle inside would be a _________.
Fluorescent lamp outlet
Illumination is measured in _______. ( illumination is the levels of light it takes to read or see, the brightening of the light.)
Foot candles
The purpose of a western union splice is _______.
For the purpose of strengthening a splice
60 cycle frequency travels 180 degrees in how many seconds?
Formula: { Per-second = cycles x 360 degrees } 60 x 360/180 = 21600/180 = 120 or 1/120
The valence electron of a conductor is also called a _________.
Free electron
Which of the following can vary with AC but not with DC
Frequency
A ______ is a braking system for an electric motor.
Friction braking, plugging, dynamic braking
An overcurrent protective device with a circuit opening fusible part that is heated and severed by the passage of overcurrent through it is called a ______.
Fuse
The neutral conductor shall not be _______.
Fused
Two metals of different materials shall not be joined together in order to avoid the __________.
Galvanic - is corrosion
A branch circuit that supplies a number of outlets for lightning and appliances is a _______ branch circuit.
General purpose
A ______ is a machine used to transform mechanical energy into electrical energy.
Generator
One of the essential functions of any switch is to maintain a ________.
Good low-resistance contact in the closed position
The greatest voltage drop in a circuit will occur when the _____ the current flow through that part of the circuit.
Greater
A test lamp using a light bulb is used to test a _________.
Ground check
Circuits are _______ to limit excess voltage to ground, which might occur from lightning or exposure to other higher voltage sources.
Grounded
Concrete, brick or tile walls are considered as being _______.
Grounded
Indentified, as used in the code in reference to a conductor or it's terminals, means that such a conductor or terminal is to be recognized as ________.
Grounded
A meter used to test the armatures and stators of electric motors, generators, and other equipment for a short circuit is called a ____.
Growler
A wire or other mechanical member having one end secured and the other end fastened to a pole maintained under tension is a ____.
Guy
_______ is a rod , wire, or other appliance for stiffening a pole, or for steadying a system of overhead wires.
Guy
A fusestat is different than the ordinary plug fuse because a fusestat ______.
Has different size threads
A low energy power circuit _______.
Has its power supplied by transformers and batteries
The wattmeter _______.
Has voltage and current coils to measure real power
Standard lengths of conduit are in 10 foot lengths. A required feeder raceway is 18 yards in length, how many lengths of 10 foot conduit would you need?
(yard = 36 inches) , ( foot = 12 inches), 36 / 12 = 3 foot, 18 / 3 = 6
A minimum thickness of _____ inch/inches of concrete over conduits and raceways should be used to prevent cracking.
1
Fixtures supported by theframing members of suspended ceiling systems shall be securely fastened to the ceiling framing member by mechanical means such as ________.
1) bolts or screws. 2). Rivets. 3). Clips identified for this use
Electrical equipment can be defined as _______.
1) fittings, 2) appliances, 3) Devices, 4) fixtures
A toaster will produce less heat on low voltage because _________.
1) it's total watt output decreases, 2) the current will decrease, 3) the resistance has not changed
When the ground resistance exceeds the allowable value of 25 ohms, the resistance can be reduced by ______.
1) paralleling ground rod, 2) using a longer ground rod, 3) using a large diameter ground rod, 4) chemical treatment of the soil
What are the most conductive to lest conductive?
1) silver, 2) copper, 3) gold, 4) aluminum, 5) zinc, 6) nickel, 7) brass, 8) bronze, 9) iron, 10) platinum, 11) steel, 12) lead
In relation to a transformer, the ratio 20:1 indicates that
1) the rare 20 turns in the primary and 1 turn in the secondary, 2) secondary voltage is 1/20 of the primary voltage, 3) for every 20 turns on the primary, there is one turn on the secondary.
A ______ box may be weatherproof
1) watertight, 2) rainproof, 3) raintight
_______ means so constructed or protected that exposure to the weather will not interfere with successful operation.
1) weather proof, 2) raintiight, 3) watertight
Where conductors carrying alternating current are installed in metal enclosures or metal raceways, they shall be so arranged as to avoid heating the surrounding metal by induction, to accomplish this _______ shall be grouped together.
1). All phase conductors, 2). Where used, the neutral, 3). All equipment grounding conductors
A _____ squirrel cage motor can be started at full voltage.
1). Design A. 2). Design B. 3). Design C. 4). Design D
When mounting electrical equipment, wooden plugs driven into holes in _______ shall not be used.
1). Masonry. 2). Concrete, 3). Plaster
Grounding conductors running with circuit conductors may be ________.
1). Uninsulated, 2). A continuous green, if covered, 3). Continuous green with yellow stripe, if covered
Which of the following would improve the resistance to earth?
1). Use multiple ground rods, 2). Treat the soil, 3). Lengthen the ground rod
Enclosed means, surrounded by a ______ which will prevent persons from accidentally contacting energized parts.
1). Wall 2). Fence, 3). Housing or case
When stripping insulation from an aluminum conductor _______.
1.) remove insulation as you would sharpen a pencil, 2.) peel the insulation back and then cut outwards
Unity power factor, which means that the current is in phase with the voltage, would be _______.
1.0
The average dry cell battery gives an approximate voltage of _______.
1.5V
The hot resistance of an incandescent lamp is approximately _______ time it's cold resistance.
10
Branch circuit conductors shall have an ampacity not less than ______.
100% of the load to be served
A 3 ohm, a 6 ohm, a 9 ohm, and a 12 ohm resistor are connected in series. Which resistor will consume the most power ?
12 ohm
In a 3-phase circuit, how many electrical degrees separate each phase?
120
Service drop conductors not in excess of 600 volts shall have a minimum clearance of _______ feet over residential property and driveways, and those commercial areas not subject to truck traffic.
15
Receptacles installed on _____ ampere branch circuit shall be of the grounding type.
15 and 20
A fixture that exceeds _______ in any dimension shall not be supported by the screw shell of a lamp holder.
16"
In other than residential calculations, an ordinary outlet shall be calculated at ________.
180va
On a delta three - phase four - way secondary, how many hot wires may use the common neutral?
2
If the primary winding of a 10 to 1 step down transformer has 20,000 turns, the secondary winding should have ______ turns.
2000
Three horsepower is equivalent to ______ watts
2238 watts, ( 1 horsepower = 746 watts ), ( 746 watts x 3 = 2238 watts )
How many kw hours are consumed by 25-60 watt light bulbs burning 5 hours in a 120V circuit?
25w x 60w = 1500 x 5(hours) = 7500w/1000w(1kw) = 7.5
A three-phase, 6-pole AC alternator 34 kva, on a Y-connected system. During one complete mechanical rotation (360 degrees) will have _____ electrical rotations.
3
A load is considered to be continuous if it is expected to continue for ______.
3 hours
A 3 ohm, a 6 ohm, a 9 ohm, and a 12 ohm resistor are connected in parallel. Which resistor will consume the most power ?
3 ohm
A wire has a resistance of 5 ohms. What will be the resistance of another wire of the same material three times as long and half the cross sectional area?
3 x 5 ohms =15 ohms, 15 ohms / .5 (sca) = 30 ohms
A length of wire has a resistance of 10 ohms. What is the resistance of a wire of the same material three times as long and twice the cross-sectional area?
3(times as long) x 10 ohms = 30 ohms, 30 / 2(twice the cross-sectional area) = 15 ohms
The type of AC system commonly used to supply both commercial light and power is the _______.
3-phase, 4-wire
What is the normal taper on a standard conduit thread-cutting die?
3/4 inch per foot
The rating of the largest size regular plug fuse is ______ amperes.
30
Listed ceiling (paddle) fans that do not exceed _____ pounds in weight, with or without accessories, shall be permitted to be supported by outlet boxes identified for such use.
35
In general, motors are designed to operate in a maximum ambient temperature of ____ unless specifically designed for a higher temperature.
40 Celsius
What is the maximum number of overcurrent devices allowed in a lighting and appliance panelboard
42
Rigid metal conduit is permitted for wiring in hazardous locations if the conduit is threaded and made up wrench tight with at least _____ full threads.
5
A fixture that weighs more than ______ shall be supported independently of the outlet box.
50 pounds
A fixture that weighs more than ______ pounds shall not be supported by the screw shell of a lamp holder.
6
When rigid metal conduits are buried the minimum cover required by the Code is ________.
6 inches
A 6 volt lead-acid battery has an internal resistance of 0.01 ohms. How much current will flow if the battery has a short circuit?
600 amps
The code considers low voltage to be ________.
600volts or less
The output rating of a one horsepower motor is _________.
746 watts
It shall be permissible to apply a demand factor of ______ to the nameplate- rating load of four or more appliances fastened in place served by the same feeder in a dwelling.
75%
A ground rod shall not be less than ______ feet in length.
8
The rating of any one portable appliance shall not exceed ________ percent of the branch circuit rating.
80
A one -quarter bend in a raceway is equivalent to an angle of ______ degrees.
90
An ohmmeter consists of a meter movement in series with _____.
A battery
A capacitor stores _______.
A charge
The primary and secondary winding of a transformer always have _________.
A common magnetic circuit
To increase the range of an AC ammeter which one of the following is most commonly used?
A current transformer
A commutator is _______.
A device for causing the alternating currents generated in the armature to flow in the same direction in the external circuit
A dynamo is ______.
A machine for converting mechanical energy into electrical energy
Permeability is ________.
A measure of the ease with which magnetism passes through any substance
The best thing to cut PVC conduit within a tight area is _______.
A nylon string
What is a fusestat?
A screw in type of fuse
Which of the following will not cause a major error in an ohmmeter reading?
A small change in the resistance to be measured
In the course of normal operation the instrument which will be least effective in indicating that a generator may overheat because it is overloaded, is _______.
A voltmeter
An electrical condenser is best defined as _______.
A wrapping of many layers of metal foil set apart by waxed paper
When a person is burned the basic care steps are _____.
A) cover and cool the burned area, B) care for shock, C) prevent infection
Before removing the ammeter from a current transformer, it's secondary emf must be short- circuited in order to avoid ________.
A) high secondary emf, B) increase in iron loss, C)excessive heating of the core
Capacitors are used in electric circuits to _______.
A) sore energy, B) introduce, C) produce a low opposition path to high frequencies
In making a resistance test, remember that the resistance of a short circuit is __________.
Approximately zero
Reactance will cause the current in a circuit to vary only when _______.
AC current flows
Which of the following is equipped with slip rings?
AC generator
Tungsten-filament lamps can be used on _______ circuit
AC or DC
Service heads and goosenecks in service entrance cable shall be _______ point of attachment of the service drops to the building.
Above the
Impedance is present in the following type of circuit:
Ac only
A junction box above a lay-in ceiling is considered _______.
Accessible
The connection of a ground clamp to a grounding electrode shall be _________.
Accessible
A clamp - on ammeter will measure ________.
Accurately only when clamped perpendicular to a conductor
The term "open circuit" means ________.
All parts of the circuit are not in contact
To connect a voltmeter in parallel to read an IR drop _________.
Allow the circto remain as is and connect the meter across both points
A wattmeter is a combination of which two of the following meters ?
Ammeter and volt meter
The current - carrying capacity of conductors expressed in amperes is _______.
Ampacity
To fasten an outlet box between the studs in a wall constructed of metal lath and plaster, tubes you would use _______.
An approved box hanger
Hysteresis losses ______.
Are caused by high frequency alternating current in a coil with an iron core
An electrician should not wear shoes that have sponge rubber soles while working mainly because they _______.
Are easily punctured when stepping on a nail
The continuity of an electrical circuit and be determined in the field by the means of _______.
Bell & battery set
The permanent joining of metallic parts to form an electrically conductive path that will ensure electrical continuity and the capacity to conduct safely any current likely to be imposed is known as ________.
Bonding
In a transformer, the primary circuit sees the impedance of the _____ winding.
Both primary and secondary
The _____ circuit is that portion of a wiring system beyond the final overcurrent protection.
Branch
You would use an approved _____ to protect conductors from abrasion where they enter a box.
Bushing
A ________ is an enclosure designed either for surface or flush mounting and provided with a frame, mat, or trim in which a swinging door or doors are or may be hung.
Cabinet
Fractional horsepower universal motors have brushes usually made of ________.
Carbon
Which of the following is the poorest conductor of electricity?
Carbon
Which type of the following portable fire extinguishers should be used on a live electrical fire?
Carbon dioxide
A fuse puller is used in replacing ______.
Cartridge fuse
The start winding of a split-phase induction motor is switched out of the circuit by a device called _________.
Centrifugal switch
What chapter in the Code is Mobile Homes referred to?
Chapter 5
Sometimes copper conductors are coated (tinned) to help prevent _______.
Chemical reaction
A device that reverses the magnetic field polarity to keep a DC motor rotating is a/an _______.
Commutator
A repulsion motor is equipped with a _______.
Commutator
A universal motor has brushes that ride on the _______.
Commutator
In a DC generator , a _______ is used to convert AC output of the armature coils into DC.
Commutator
Mica is commonly used in electrical construction for ______.
Commutator bar separators
_______ is a wiring method using knobs, tubes, and flexible non-metallic tubing for the protection and support of single insulated conductors concealed in hollow spaces of walls and ceiling of buildings.
Concealed knob and tube wiring
A _____ helps prevent arcing in movable contacts.
Condenser
A ________ helps prevent arcing in movable contacts.
Condenser
_______ is the ability of a material to permit the flow of electrons
Conductance
Which of the following has the least number of valence electrons?
Conductor
In a residence the wall switch controlling the ceiling light is usually _______.
Connected in one line only
A foreman in charge of a crew of men preparing to work on a low voltage tension circuit should caution them to _____.
Consider the circuit hot at all times
______ is the resistance at the point of contact of two conductors or one conductor and another surface.
Contact resistance
The main purpose of a photovoltaic cell is to __________.
Convert light to electrical energy
Copper is used for the tip of a soldering iron because _______.
Copper is a very good conductor of heat
Which of the following is/are generally used for field magnets?
Copper, steel, and wrought iron
____ is a glow discharge that occurs in electric conductors where the insulation has electric stress
Corona
The effect of a discharge of electricity due to ionization of surrounding air by high voltage is ________.
Corona effect
Silver and gold are better conductors of electricity than copper; however, the main reason copper is used is its ______.
Cost is less
The normal rotation of an induction motor is ______ facing the front of the motor. ( the front of a motor is the end opposite the shaft).
Counterclockwise
A ______ conductor is one having one or more layers of non-conducting materials that are not recognized as insulation.
Covered
When the size #12 of a stranded wire is referred to, this number specifies the:
Cross-sectional area of the wire
A shunt is used to measure ________.
Current
In magnetic and electric circuit analogy, magnetic flux is the analog of _______
Current
Which of the following is not the force which moves electrons?
Current
A common fuse and circuit breaker work on the principal that _______.
Current develops heat
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 ________.
Currents would circulate through individual raceways
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 _________.
Currents would circulate through individual raceways
A tap tool is a tool used to _____.
Cut internal threads
Voltage in a generator is produced by _______.
Cutting lines of force
On a drawing, a circle with the letter B stands for _______.
Outlet with blank cover
A shunt is sometimes used to increase the range of an electrical measuring instrument. The shunt is normally used when measuring _____.
DC amperes
A motor with a wide speed range is a _______.
DC motor
Installing more than three current carrying conductors in the same conduit requires _______.
Defraying of ampacity
Installing more than three current carrying conductors in the same conduit requires ________.
Defraying of ampacity
What is the function of a neon glow tester?
Determines if circuit is alive, 2). Determines polarity of DC circuits, 3). Determines if circuit is AC or DC
An instrument used to check the motor shaft alignment is called a ________.
Dial indicator
A generator exciter uses ______ current
Direct
Sometimes mercury toggle switches are used in place of a regular toggle switch because they _______.
Do not wear out as quickly
A location classified as ______ may be temporarily subject to dampness and wetness.
Dry
The best type of fire extinguisher for an electrical fire is a __________.
Dry chemical extinguisher
_______ is a pliable raceway - ( able to bend easily without breaking )
ENT
On smaller gauges of wire, they are pencil-stripped to prevent _______
Nicks in the wire
Because aluminum is not a magnetic metal, there will be ______ present when aluminum conductors are grouped in a raceway.
No heating due to hysteresis
A value assigned to a circuit or system for the purpose of conveniently designating its voltage class is ______.
Nominal voltage
Rosin is preferable to acid as a flux for soldering wire because rosin is ________.
Non corrosive
Action requiring personal intervention for its control is called _______.
Non-automatic
The important function of a type S fuse is ________.
Non-interchangeable
Frequency is determined by the ______ of an alternator.
Number of poles and the rotation speed of the armature
A/an ______ requires its own power source.
Ohmmeter
Rubber insulation on an electrical conductor would quickly be damage by continuous contact with _______.
Oil
A laminated pole is _______.
One built of layers or iron sheets, stamped from sheet metal and insulated
In a enter-tapped circuit, ________ transformer secondary voltage is utilized.
One half
An exposed wiring method using cleats , knobs, tubes and flexible tubing for the protection and support of single insulated conductor run in or on a building and not concealed by the building structure is ________.
Open wiring on insulators
The assigned color for the high-leg conductor of a three-phase, 4-wire delta secondary is ______.
Orange
In general, the most important point to watch in the operation of transformers is the ________.
Temperature
Something that would effect the ampacity of a conductor would be _______.
Temperature
Where the ______ is likely to be high, asbestos insulation on the conductor would be a good choice.
Temperature
For voltage and current to be in phase, ________.
The circuit impedance has only resistance and the voltage and current appear at their zero and peak values at the same time.
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 ______.
The conductor will not turn off
If a live conductor is contacted accidentally, the severity of the electrical shock is determined primarily by _______.
The contact resistance
If a bare live conductor is touched accidentally, the severity of the electric shock is determined primarily by ________.
The contact resistance between the bare wire and the person at the point of contact
When one resistance in a series circuit is open ________.
The current is zero in all the resistances
When soldering conductors, flux is used _______.
To keep the surfaces clean
The voltage of a circuit is best defined as ______.
The effective difference of potential between two conductors
If the spring tension on a cartridge fuse clip is weak, the result most likely would be _______.
The fuse clips would become warm
In a series circuit with unequal resistance _____.
The highest resistance has the highest voltage
Hysteresis is _______.
The lagging of magnetism, in a magnetic metal, behind the magnetizing flux which produces it
The voltage produced by electromagnetic induction is controlled by ________.
The number of lines of flux cut per second
Wing nuts are useful on equipment where _______.
The nuts must be removed frequently
When using an ohmmeter, disconnect the applied voltage from the circuit being checked because ________.
The ohmmeter has its own internal battery
The property of a circuit tending to prevent the flow of current and at the same time causing energy to be converted into heat is referred to as ______.
The resistance
When the battery cells are in series, voltages add; while current capacity is _______.
The same as one cell
An electron is _____.
The smallest part of an atom with a negative charge
Single conductor cable runs within a building are generally more common than multicable runs because ________.
The splicing is easier
When soldering two copper conductors together, they are kept clean while heating by _______.
The use of flux
When soldering two copper surfaces together, they should be kept clean while heating by ______.
The use of flux
In a parallel circuit with an unequal resistance on each branch ________.
The voltage across each branch is equal
What is the function of the zero adjust control in a multimeter
The zero point is corrected with the help of this control
______ are permitted to protect motor branch circuit conductors from overload.
Thermal relays, inverse time circuit breakers, or time delay fuses
If the end of a cartridge fuse becomes warmer than normal, you should _________.
Tighten the fuse clips
Electrical continuity is required by the electrical code for metallic conduit _______.
To assure a ground fault path
A somewhat rare metal used as a filament in incandescent lamps and vacuum tubes.
Tungsten
A function of a relay is to ______.
Turn on another circuit
The standard classification of branch circuits applies only to those circuits with _______ outlets.
Two or more
Two switches in one box under one face-plate is called a _______.
Two-gang switch
In sockets, extension cords is protected by means of the _______ knot.
Underwriters knot - is a technique for tying lamp cord or appliance cord at the point where it joins the plug or socket.
A sing-pole switch to operate a light will have the wiring connected in the _____ conductor.
Ungrounded
In a DC circuit, the ratio of watts to voltamperes is _______.
Unity
The power factor of an incandescent light bulb would be _________.
Unity
A type of single phase motor that can be operated on ether Ac or DC is a ________ motor
Universal
To cut wiremold you would _____.
Use a hacksaw and remove the burr with a file.
When installing an instrument meter on a panel, to obtain accurate mounting _________.
Use a template
To increase the life of an incandescent light bulb you could ______.
Use at a lower than rated voltage
Electrons on the outer shell are called ________ electrons.
Valence
Rheostats and potentiometer are types of _______ resistor
Variable
______ duty is a type of service where both the load and the time intervals may have wide variations.
Varying
The electric pressure or electromotive force is measured by the _____.
Volt
The transformer output is measured by ________.
Volt-amps
The output of a 3 phase transformer is measured in units called _______.
Volt-amps ( because the output is out of phase)
The electric pressure of a conduit would be the ______.
Voltage
A transformer transforms _________.
Voltage and current
The armature current drawn by any DC motor is proportional to the ______.
Voltage applied
For current to flow the very basic circuit requirements are _______.
Voltage source and a conductor
When an electric current is forced through a wire that has considerable resistance, the ______.
Voltage will drop and wire will heat up
A _____ cell is another name for a galvanic cell.
Voltaic
A multimeter is a combination of _________.
Voltmeter, ohmmeter, ammeter
If a co-worker is burned by acid from a storage battery, the proper first aid treatment is to wash with ______.
Water and apply vaseline
An instrument that measures electrical energy is called the _______.
Watthour meter
Conduit installed in a concrete slab is considered a _______.
Wet location
A location classified as dry may be temporarily subject to ________.
Wetness and dampness
The more accurate method of measuring low resistance in DC circuit is accomplished by using a/an ______ bridge
Wheatstone
A transformer steps a voltage down from 117 volts to 6 volts. The ratio of transformation is ________.
117 V / 6 V = 19.5 then the ratio is 19.5:1
A _______ is nota standard size fuse.
75 amp
Electrical power is almost exclusively generated, transmitted and distributed by three-phase systems because it _______.
A) cost less than single-phase apparatus, B) is more efficient, and C) uses less material for a given capacity.
What is a diffuser?
Also called a light diffuser or optical diffuser
Electrons is a Greek word for _______.
Amber
An advantage of an electromagnet over a permanent magnet is that ______.
An electromagnet can be switched on and off
The _______ is defined as the shortest distance measured between a point on the top surface of any direct buried conductor, cable, conduit and the top surface of finish grade.
Cover
In a DC circuit, inductance and capacitance are irrelevant in circuit analysis due to _______.
DC supply has no frequency
When the temperature of a conductor is decreased, the resistance will be _______.
Decreased
A large series motor should not be started without some mechanical load on it because it will _______.
Develop excessive speed and damage itself.
Bonding provides electrical continuity and safety conducts any _____.
Fault current that may occur
The _____ is used in a DC motor to control the speed.
Field winding
The 20/1 ratio on a transformer indicates _________.
For every 20 turns on the primary, there is one turn on the secondary
Corona occurs between two transmission wires when they ________.
Have a high potential difference
In a series circuit with unequal resistances the ______.
Highest resistance has the highest voltage
An ideal step-up transformer with 100 turns in the primary and 2500 turns in the secondary carries a load of 2 amps in the secondary windings. The current of the primary winding is _______.
IP/Is = NS/NP, IP/2 = 25/1, IP =(25/1)2 , IP = 25 x 2 = 50 amps
Light is converted into electricity _______.
In a photovoltaic cell
The purpose of battery cells connected in parallel is to ________.
Increase in current capacity
________ is the process by which one conductor produces or induces a voltage in another conductor even though there is no mechanical coupling between the two conductors.
Induction
Those materials that can be charged by being rubbed against a suitable other material are usually _______.
Insulators
A coloumb ______.
Is an extremely large number of charge carries
A form of air switch in which the moving element is a hinged blade wedge between stationary contact blades when closed is a ______ switch.
Knife
Steel is hard to magnetize because of its __________.
Low permeability-( is the measure of the resistance of a material against the formation of a magnetic field )
A step-down transformer ________.
Lowers the voltage and increases the current.
In electricity, the negative electric charge refers to ________.
Neutrons
Grease is a lubricant that is basically a combination of _______.
Oil and soap
WHen a circuit breaker handle is operated vertically rather than horizontally, the "up" position of the handle shall be the _____ position.
On
The continuity of a coil of winding may be determined by measuring the resistance of the coil. If the resistance measured is infinite, the coil winding is ________.
Open
To connect an ammeter in series _________.
Open the circuit at one point and use the meter to complete the circuit.
In motors and transformers, the reason for the thin layer of varnish over the copper oil pattern is to prevent _______.
Oxidation
In electricity, the positive electric charge refers to ________.
Protons
To increase voltage output, battery cells are connected in _______.
Series
A ________ is nameplate data that will tell whether or not the motor is allowed to develop more than its rated nameplate horsepower without causing deterioration of its insulation.
Service factor
Branch Circuits are classified according to the maximum ________.
Setting of the overcurrent device
The proper way of measuring an unknown voltage with a multi-tester is to _______.
Start measuring at the highest rang
The capacitor in a capacitor-start induction-run AC motor is connected in series with the _______ winding.
Starting
An inductor works by ______.
Storing energy as a magnetic field
If the needle of the VOM will no longer align with the zero-ohm mark at the lowest range of resistance but will align on the other resistance range, the probable cause is the _______.
Supply battery is weak
A general term covering an assembly of assemblies of devices for the interruption, control and metering of electric power is called the ______.
Switchgear
The voltage per-turn of the primary of a transformer is ______ the voltage per-turn of the secondary
The same as
The purpose of a ballast in a fluorescent lamp assembly is ________.
To limit the current through the lamp
The filament of an incandescent lamp is usually made of ______.
Tungsten
A ____ lamp is also called a quartz lamp
Tungsten halogen
A squirrel cage induction motor has a _______ starting torque.
Very low
What rating of a resistor determines its ability to absorb heat?
Wattage
The physical size of a resistor that determines the ability of a resistor to absorb heat is in ________.
Watts
Lampholders installed in wet or damp locations shall be of the _______ type.
Weatherproof