ELC 101
Wood
Which of the following would be considered a good electrical insulator?
0
If a DC voltmeter is connected to an AC circuit with an applied voltage of 240 V, the meter will read ___.
25
If four resistors, each with a value of 100 ohms, are connected in parallel, the total resistance of the of the circuit is ___ ohms.
Into 1
The reciprocal of any number is that number divided ___ .
Henry
The standard measure of inductance is the ___.
Inductive
When the leads of the compensating winding of a universal motor are shorted together, the connection is known as ___ compensation
Resistance
When the selector switch of a meter is turned to a new scale, steps of ___ are inserted in the circuit to increase the range or are removed from the circuit to decrease the range.
Current induced into the armature
When using Flemings generator rule, the center finger shows the direction of the ___.
Field flux
When using Flemings generator rule, the forefinger points in the direction of the ___.
Thrust
When using Flemings generator rule, the thumb points in the direction of the ___.
I= E/R
When using Ohms law to determine amperage, the formula you would use is ___ .
E= I x R
When using Ohms law to determine voltage, the formula you would use is ___ .
Divide the total of R(1) times R(2) by the total of R(1) plus R(2)
When using the product over sum method of determining the total resistance of parallel circuit, you would ___ .
Insulation trade name, conductor identification code letter and maximum operating temperature of the conductor
Which of the following are included in the NEC table 310.104A
Aluminum
Which of the following is an example of a good conductor of electricity?
Photons
___ are massless particles of pure energy.
Autotransformers
___ are often used by power companies to provide voltage regulation to large power lines.
Braided
___ cable is less affected by the skin effect.
Watts and true power
___ can be produced in AC circuits only when both current and voltage are either positive or negative.
Photons
___ can be produced when the electrons move from one energy level to another.
Silver
___ is the best natural conductor of electricity.
Lenz's
___ law states that an induced voltage or current opposes the motion that causes it.
Volts
___ push current through a wire but cannot flow through the wire.
Sine
___ waves are so named because the voltage at any point along the wave form is equal to the maximum, or peak, value times the sine of the angle of rotation.
Foot-pound
A ___ is the amount of force required to raise a one-pound weight one foot.
Current relay
A ___ operates on the principle of magnetic field instead of expanding metal.
Linear
A ___ wave is one in which the voltage rises at a constant rate with respect to time.
Centrifugal
A basic law of physics states that a spinning object will pull away from its center point and that the faster it spins, the greater the ___ force becomes.
Diameter
A circular mil is the ___ of the wire in mils squared.
Henry
A coil has an inductance of one ___ when a current change of one ampere per second results in an induced voltage of one volt.
Air core
A coil wound on a nonmagnetic core material such as a wood or plastic is referred to as a(n) ___ inductor.
Grounding
A conductor connected to the case of an appliance to provide a low-resistance path to ground is called a(n) ___ conductor.
Power, power
A good rule for any transformer is that ___ in must equal ___ out.
Damp
A location that is covered and not likely to be saturated by water is a ___ location.
Dry
A location that is not normally subject to dampness or wetness is called a ___ location.
Wet
A location that is subject to saturation by water is called a ___ location.
1800
A motor that has 4 stator poles will have a rated speed of approximately ___ RPM.
Load
In an electrical circuit, the ___ offers resistance to the circuit and limits the amount of current that can flow.
Weber
In magnetic measurement, 100,000,000 lines of magnetic flux are equal to one ___.
Synchronous
In motors, the speed of the magnetic rotating field is called the ___ speed.
Always equal
In parallel circuits , the voltage across each branch of the circuit is ___.
Divided by the number of resistors
In parallel circuits, when all resistors are of equal value the total resistance is equal to the value of one individual resistor___ .
Maximum voltage drop and resistance
In some cases, such as for long wire runs or for the windings of transformers and motors, the electrician must be able to determine the correct conductor size by computing the ___ of the conductor.
Ground
In voltage divider circuits, ___ is often used to provide a common reference point to produce voltages that are above or below ground.
Series, parallel and combination
In which of the following types of circuits can the total power of the circuit be determined by adding the power dissipation of all the parts of the circuit?
Photons
Producing electricity from light involves the use of particles called ___.
Seebeck
Producing electricity with heat is referred to as the ___ effect.
Mutual
The ability of one coil to induce a voltage into another coil is called ___ induction.
Power
The amount of core material needed for a particular transformer is determined by the ___ rating of the transformer.
Must equal the current returning to the source
The amount of current leaving the source ___.
Amperage and resistance
The amount of voltage required to push the electrons through the circuit is determined by the amount of ___ .
Proportional to
The average voltage is ___ the peak, or maximum, value of the wave form and to the length of time it is on as compared to the length of time it is off.
Higher than
The capacitor-start induction-run motor produces a starting torque that is ___ that of the resistance-start induction-run motor.
Field effect transistors
The input impedance used to limit the flow of current through digital meters is accomplished by using ___.
E
The letter ___ is used to represent voltage in algebraic formulas.
3
The maximum amount of voltage drop permitted in a circuit is ___ % of the applied voltage.
60
The most common frequency used in electrical generation in the United States and Canada is ___ hertz.
Magnetism
The most common method of producing electricity is ___
Primary winding
When a toroid current transformer is used to measure AC current, the main power line acts as the ___ and is considered to be one turn.
AC
When a universal motor has the leads of its compensation winding shorted together, it must be operated on ___.
Conductive
When a universal motor is operated on AC and the compensation winding is connected in series with the armature, it is known as ___ compensation.
Series
When connecting a dual voltage motor for high voltage, the leads must be connected in ___.
Grounds
When testing a transformer, if one ohmmeter lead is connected to a transformer winding and the other is connected to the transformer frame, you are testing the transformer for ___.
Continuity
When testing a transformer, if one ohmmeter lead is connected to the lead of a transformer winding and the other ohmmeter lead is connected to the other lead of the same winding, you are testing the transformer for ___.
Amperage
In a series circuit, the ___ is the same at any point in the circuit.
Ammeter shunt
A(n) ___ is a low-resistance device used to conduct most of the circuit current away from the meter movement.
Joule
A(n) ___ is the amount of work done by one watt for one second.
Oscillators
Square waves are generally produced by electronic devices called ___.
Ohmmeter
A(n) ___ must never be connected to a circuit when the power is turned on.
Element
A(n)___ is a substance that cannot br chemically divided into a simpler substance
X
Secondary windings of transformers are labeled with the letter ___.
Current
According to Ohms law, an increase of resistance must cause a proportional decrease of ___ .
Times
According to the general voltage divider formula, the voltage drop across any particular resistance is equal to the total circuit current ___ the value is that resistor.
Inductor
An exponential curve shows the rate at which current increases or decreases in a(n) ___.
1 to 1
An isolation transformer whose main purpose is to reduce voltage spikes will have a turns ratio of ___.
Valence
Any electrons located in the outer shell of an atom are known as ___ electrons.
310
Article ___ of the National Electrical Code deals with conductors used for general wiring.
Higher resistance than
Because the start winding is wound with smaller wire and placed near the top of the stator, it will have ___ the run winding.
Two
Since both the start winding and the run winding of a capacitor-start capacitor-run motor remain energized at all times, the motor operates as a ___-phase motor.
Autoranging
Digital meters that do not contain a range setting control are known as ___ meters.
Cycle
Each completed wave form of a sine wave is called a(n) ___.
Current
Electrical ___ is the flow of electrons.
Grounding
Electrical current will flow through the ___ conductor only when a circuit fault develops.
10 to 1
If a transformer has 1000 turns in the primary winding and 100 turns in the secondary winding, the turns ration of this transformer is ___.
Neutral
In a distribution transformer, the center tap is grounded and becomes the ___ conductor.
Frequency
In a sine wave, the number of complete cycles that occur in one second is called a ___.
RMS
The AC voltage that will produce the same amount of power as a like value of DC voltage is called the ___.
Grounding
The ___ conductor is used to help prevent a shock hazard in the event that the hot conductor comes in contact with the case or frame of an appliance.
Grounding and neutral
The ___ conductor provides the return path and completes the circuit back to the power source.
Hot-wire relay
The ___ functions as both a starting relay and an overload relay.
Peak
The ___ is measured from zero to the highest value obtained in either the positive or negative direction.
Ohmmeter
The ___ must provide its own source of power.
Sine
The ___ wave is produced by all rotating machines.
Protons
The number of ___ in the nucleus determine what kind of element an atom is.
Piezoelectric
The production of electricity by pressure involves the striking, bending, or twisting of certain crystals that is referred to as the ___ effect.
Frequency
The skin effect is proportional to the ___. As the ___ increases, the skin effect increases.
Series, parallel and combination
The total amount of power in a ___ circuit is equal to the sum of the power used by all the parts.
Impedance
The transformer ___ is determined by calculating the percentage of variable voltage as compared to the rated voltage of the high voltage winding.
6
Three resistors, with values of 10 ohms, 20 ohms, and 30 ohms, are connected in parallel and the circuit has a voltage of 120 volts with an amperage of 2.5 amps. The total current of the 20-ohm branch is ___ amps.
Remove the stator winding and turn it around
To reverse the direction of a shaded-pole motor, you need to ___.
