DC/AC Midterm
____ states that current flows from the most positive point in a circuit to the most negative.
The conventional current flow theory
____ states that since electrons are negative particles, current flows from the most negative point in the circuit to the most positive.
The electron theory
According to the general voltage divider formula, the voltage drop across any particular resistance is equal to the total circuit current ____ the value of that resistor
Times
____________________ indicates the plus and minus limits of a resistor's ohmic value.
Tolerance
A ____________________ resistor is a resistor whose values can be changed or varied over a range.
Variable
In a series circuit, the sum of all the voltage drops across all the resistors must be equal to the ________ applied to the circuit.
Voltage
___________ is the force that pushes the electrons through a resistance
Voltage
____________________ is defined as electromotive force.
Voltage
A principal function of resistors is to produce a ____, which is used to create the different ranges in multirange voltmeters.
Voltage Divider
____ are used to provide different voltages between certain points of a circuit.
Voltage Dividers
____ indicates the amount of voltage necessary to push the current through the limiting element.
Voltage Drop
_______ can be determined by observing the direction of current flow through the circuit.
Voltage Polarity
____ push current through a wire but cannot flow through the wire.
Volts
____ is a measure of the amount of power being used in a circuit.
Wattage
Electrical energy must be changed or converted into some other form of energy before there can be ____.
Watts
____ resistors can operate at higher temperatures than any other type of resistor.
Wire-wound
____ resistors are fixed resistors that are made by winding a piece of resistive wire around a ceramic core.
Wire-wound resistor
Which of the following would be considered a good electrical insulator?
Wood
If a series circuit has three resistors and two amps flow through each resistor, the total amperage for the circuit is ____ amps.
2
A potentiometer is a variable resistor with ____ terminals.
3
Resistors that have a tolerance of plus/minus 20% have ____ color bands.
3
The maximum number of electrons that can be contained in any orbit is
32
The 40 amp breaker at 80% load will carry how many amps?
32 Amps
Using Ohm's Law, determine the voltage of a circuit with 40 amps and 12 ohms. ____________________
4
How much load will actually be on this circuit?
41.67
A series circuit has individual resistor values of 200 ohms, 150 ohms, 50 ohms, and 75 ohms. The total resistance of the circuit is _________ ohms.
475
The value of 5 M-ohms is ____ ohms
5 million
If a circuit has a voltage of 120 V and 20 amps, the resistance of the circuit is ____________________ ohms.
6
What next size breaker would you install?
60
The amount of electrical energy needed to produce one horsepower is ____ watts.
746
When using Ohm's Law to determine voltage, the formula you would use is ____.
E=I x R
The ground point that is made by physically driving an object, such as a ground rod, into the ground is called a(n) ________ ground.
Earth
The Greeks called amber ____, because of its ability to attract lightweight materials when rubbed with different materials.
Elektron
A(n) ____ is a substance that cannot be chemically divided into a simpler substance.
Element
T/F. Is the 40 ampere breaker large enough to carry the load?
False
T/F. The 3 principal parts of an atom are the proton ,neutron and nucleus.
False
T/F. The force that exists between two objects that contain like electrical charges is called attraction
False
The basic laws of physics states that likes attract and opposite's repel.
False
A(n) ____ is the amount of resistance that allows one ampere of current to flow when the applied voltage is one volt.
Ohm
A(n) ____________________ is the unit of resistance to current flow
Ohm
Given the voltage and the resistance, the amount of current flow in a circuit can be determined by using __________.
Ohm's Law
In its simplest form, ____________________ states that it takes one volt to push one amp through one ohm.
Ohm's Law
The unit of measure for resistance is ____________________.
Ohms
The formula to use to find power when voltage and current are known is __________________
P=E x I
One function of ____________________ is to limit the flow of current through a circuit
Resistors
A series circuit has five resistors and the total voltage applied to the circuit is 120 volts. Four of the resistors have voltage drops of 35 volts, 25 volts, 30 volts, and 20 volts. The voltage drop of the fifth resistor is _________ volts.
10
When the color gold is used in the multiplier band, it means to divide the numeric value of the first two bands by ____.
10
When the color silver is used in the multiplier band, it means to divide the numeric value of the resistor by ____.
100
A series circuit contains four resistors and the total resistance of the circuit is 420 ohms. Three of the resistors have values of 70 ohms, 80 ohms, and 150 ohms. The value of the fourth resistor is ___________ ohms
120
A rheostat is a variable resistor with ____ terminals
2
Using Ohm's law, it would take ________ volts to push 4 amps of current through 20 ohms of resistance.
80
A circuit with little or no resistance in it is called ____.
A short Circuit
Carbon resistors will change their value because of ____.
Age or Overheating
Which of the following is an example of a good conductor of electricity?
Aluminum
In a series circuit, the ____ is the same at any point in the circuit.
Amperage
The amount of voltage required to push the electrons through the circuit is determined by the amount of ____.
Amperage or Resistance
The ____ is a measurement of the amount of electricity that is flowing through a circuit.
Ampere
In a series circuit, the sum of the voltage drops equals the ____________.
Applied Voltage
The basic building block of the universe is the
Atom
A _________________________ is defined as the amount of heat required to raise the temperature of one pound of water one degree Fahrenheit
BTU- British Thermal Unit
____ resistors are made from a compound of carbon graphite and a resin bonding material.
Carbon Resistors
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
Centrifugal
A point used as a common connection point for other parts of a circuit, but is not actually driven into the ground is called a(n) ________ ground.
Chassis
The value of a resistor can often be determined by use of the ____________________.
Color Code
______________ law of electrostatic charges states that the force of electrostatic attraction or repulsion is directly proportional to the product of the two charges and inversely proportional to the square of the distance between them.
Columbs
Before current can flow through a circuit, a _________________________ must exist.
Complete Path
A ____ is generally made from material that contains one or two valence electrons
Conductor
Electrical ____ is the flow of electrons.
Current
T/F. The letter ____ is used to represent voltage in algebraic formulas
E
Resistors that have a tolerance of plus/minus 1%, as well as some military resistors, contain ____________________ bands of color.
Five
____ resistors have only one ohmic value, which cannot be changed or altered
Fixed
A ____ is the amount of force required to raise a one-pound weight one foot.
Foot-pound
When using the color code to determine the value of a resistor, the ____________________ band is the tolerance band, when the tolerance of the resistor is 5% or 10%.
Fourth
A circuit where a path other than the one intended is established to ground is said to be ____.
Grounded
The ____ conductor provides the return path and completes the circuit back to the power source.
Grounded and neutral
A conductor connected to the case of an appliance to provide a low-resistance path to ground is called a(n) ____ conductor.
Grounding
Electrical current will flow through the ____ conductor only when a circuit fault develops
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
All electricians should know that whenever current flows through a resistance, ____________________ is produced
Heat
When using Ohm's Law to determine amperage, the formula you would use is ____.
I=E/R
Rubber, wood, plastic, and glass are good examples of ____ materials
Insulator
The disadvantage of the metal film resistor is that ____.
It costs more than carbon resistors
In an electrical circuit, the ____ offers resistance to the circuit and limits the amount of current that can flow.
Load
The most common method of producing electricity is ____.
Magnetism
____ can be produced when electrons move from one energy level to another.
Matter
When using the color code to determine resistor values, the third band is called the ____________________ band.
Multiplier
When working with electrical equipment that requires sensitive adjustments, ____ resistors are usually used.
Multiturn Variable
A ____ charge is formed by an excess of electrons.
Negative
Producing electricity from light involves the use of particles called ____.
Photons
____ are massless particles of pure energy.
Photons
The production of electricity by pressure involves the striking, bending, or twisting of certain crystals that is referred to as the ____ effect.
Piezoelectric
The most common popular name for variable resistors is ____________________.
Pot
In a series circuit, the total power used in a circuit is equal to the sum of the ________ used by all the parts of the circuit.
Power
The atomic number of an element is the same as the number of ____ in the nucleus.
Protons
The number of ____ in the nucleus determine what kind of element an atom is.
Protons
The total amount of resistance to current flow in a series circuit is equal to the sum of the ____ in that circuit.
Resistance
The definition of _____________ is that the total resistance of a circuit can be found by adding the values of all the resistors in that circuit.
Resistance adds
Producing electricity with heat is referred to as the ____ effect.
Seebeck
A _______ circuit is a circuit that has only one path for the current to flow.
Series
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?
Series, parallel and combination
A ____ circuit is a circuit with very little or no resistance.
Short
____ is the best natural conductor of electricity.
Silver
Resistors also have a power rating in watts that should not be exceeded or the resistor will be damaged
True
T/F. A charge formed by a lack of electrons is said to be positive
True
T/F. Alternating current is bi directional
True
T/F. Basic electricity is the flow of electrons.
True
T/F. Direct current is unidirectional
True
T/F. Matter is any substance that has mass and occupies space
True
T/F. Neutrons and proton's of an atom combine to form the Nucleus.
True
When using the color code to determine resistor values, the first ____________________ bands represent number values.
Two
A potentiometer is a variable resistor used to provide a variable __
V
Any electrons located in the outer shell of an atom are known as ____ electrons.
Valence
