DC Ahmad Final
A parallel circuit composed of a 150 W and a 270 W resistor has a voltage of 120 V. What is the current in the 150 W resistor?
0.8A
A two-branch parallel circuit has a 30 W and a 15 W resistor. What is the total resistance?
10W
The National Electrical Code® _____ contains tables dealing with conductors for general wiring.
310
A three branch parallel circuit has resistors of 27 W, 56 W, and 15 W. What is the total resistance?
8.23W
The two resistors in a series circuit have voltages of 25 V and 60 V. The applied voltage is _____.
85 V
A method for finding total resistance of parallel resistors is _____.
ALL THE ABOVE
The amount of power a cell can deliver is called its _____ capacity.
Current
The d'Arsonval meter movement is operated by applying _____ current to the coil.
DC
An ion is an atom that has had a(n) _____ added or removed.
ELECTRON
Which of the following formulas is the general voltage divider formula?
EX = (Rx/Rt)Et
The amount of voltage produced by a cell depends on the materials used to make it. A list of metals showing their willingness to accept electrons is called the _____ series of metals.
Electromotive
The measurement of the specific gravity is done with a device called a _____.
Hydrometer
"The algebraic sum of the currents entering and leaving a point must equal zero" is _____.
Kirchhoff's current law
In a parallel circuit, the total resistance is _____ value resistor.
LESS THAN THE LOWEST
Circuit networks can be reduced to a single current source and a single parallel resistance. This conversion is done in accordance with _____.
Norton's theorem
Piezoelectricity refers to electricity produced by some materials when they are subjected to _____.
Pressure
The no-load voltage of a cell is greater than the normal load voltage because of the internal _____ of the cell.
Resistance
A circuit that has only one path for current flow is a _____ circuit.
Series
_____ is a measure of the amount of acid contained in water.
Specific gravity
_____ is the force that pushed the electrons through a resistance.
Voltage
A(n) _____ voltage is a voltage that is positive with respect to ground.
above-ground
An electrolyte may be made from water and an additive such as salt or a(n) _____ or a(n)
acid, alkali
A test meter that uses a scale and pointer to indicate values is a(n) _____ meter.
analog
A generator containing both series and shunt fields is called a _____ generator.
compound
The relationship of the strengths of the two fields in a generator determines the amount of _____.
d. compounding
A voltage _____ is used to provide different voltages between certain points in a circuit.
dividersx
A(n) _____ ground symbol is used to symbolize a ground point made by physically driving an object such as a rod or pipe into the ground.
earth
The process of separating elements electrically is known as _____.
electrolysis
The most important factor in ionization of a gas is _____.
electron impact
A device that is designed to open and disconnect a circuit in the event of excessive current is a _____.
fuse
The amount of voltage an electron must possess to cause ionization is called the _____.
ionization potential
Resistance is measured with a(n) _____.
ohmmeter
A series circuit has _____ path(s) for current flow.
one
When a conductor is very large it may become necessary to connect them in _____.
parallel
The ServoDisc motor is also often called a _____ motor.
printed-circuit
An ammeter is connected in _____ with the load to permit the load to limit current flow.
series
Lead-acid batteries use an electrolyte containing _____.
sulfuric acid
The _______________ in a parallel circuit is equal to the sum of the currents through all of the circuit branches.
total current flow
Kirchhoff's two laws are concerned with _____.
voltages drops and currents entering and leaving a point
A parallel circuit composed of a 10 W and a 22 W resistor. It has a voltage of 60 V. What is the current in the 10 W resistor?
6A
A voltmeter has a very _____ resistance connected in series with the meter movement
HIGH
During the charging of lead-acid batteries, it is possible that _____ will be formed. Caution should be observed because this is the most explosive element known.
Hydrogen
A cell which can be recharged is a _____ cell.
Secondary
Series field windings are connected in series with the armature. They are wound with _____ turns of fairly _____ wire.
a. few, large
In an electroplating operation, the positive terminal is called the _____.
anode
In parallel circuits, the voltage drop across any branch is the same as the _____.
applied voltage
The component of a DC generator that converts the armature AC into DC is the
commutator
The unit circular mil is equal to the _____.
diameter of the wire in mils squared
The process of depositing one type of metal onto another using electricity is called _____.
electroplating
Shunt field windings are connected in parallel with the armature. They are wound with _____ turns of fairly _____ wire.
many, small
The insulation used on conductors cannot operate in all possible temperatures. The highest allowable temperature is called the _____ temperature.
maximum operating
Most voltmeters are _____ voltmeters, meaning they are designed to use one meter movement to measure several ranges.
multirange
The current, voltage, power, and resistance in a series circuit can be found by using _____ law.
ohms
A special meter that is used to display short-duration, low-voltage pulses is called a(n) _____.
oscilloscope
Materials that increase their resistance with an increase in temperature have a _____ coefficient of temperature.
positive
Small permanent magnet motors that have lightweight rotors are often used as _____.
servomotors
In a series circuit, the _______________ is the sum of the individual resistances.
total resistance
In 1800, Alessandro Volta was experimenting with producing electricity. He called his battery a _____.
voltaic pile
A(n) _____ is designed to be connected directly across the power source.
voltmeter
The term "load" refers to the amount of _____ in a circuit branch.
CURRENT
To test wire insulation, a special type of ohmmeter is used, called a(n) _____.
MEGGER
X-rays are the result of conduction in a _____.
gas
A junction point of current paths is often called a _____.
node
A compound motor has _____ field windings.
series and shunt
A series circuit has a total resistance of 180 W and an applied voltage of 120 V. What is the current flow?
0.667 A
A three-resistor circuit has a total power of 25 W. Two of the resistors dissipate 10 W and 5 W respectively. How much power does the third resistor dissipate?
10 W
A three-branch parallel circuit has a total resistance of 385.83 W. Two of the resistors are 680 W and 1500 W. What is the value of the third resistor?
2200W
A series circuit has two resistors. The resistors dissipate 10 W and 15 W. What is the total power dissipation of the circuit?
25 W
A wire that has a diameter of 162 mils has an area of _____ circular mils.
26,244
A parallel circuit is composed of two 60 W resistors. What is the total resistance?
30W
A series circuit has a total resistance of 240 W and a current flow of 4 A. What is the applied voltage?
960 V
When a(n) _____ is used, the resistors are connected in parallel with the meter on some ranges and in series for other ranges.
Ayrton shunt
The rotating part of a generator is called the
armature
The speed of the disc servomotor can be varied by changing the amount of voltage supplied to the armature. The voltage is generally varied using _____.
b. pulse-width
A combination circuit is a circuit that contains
both series and parallel components
When using a(n) _____ ammeter, the meter is only connected to one of the lines.
clamp-on
To use Kirchhoff's law, start at some point and add the voltage drops around any _____ loop.
closed
Plating copper onto iron often involves a poisonous solid called _____.
cuprous cyanide
When a circuit has only one path, the _____ is the same at any point.
current
Moving coil meter is another name for the _____ meter movement.
d'Arsonval
One of the most common analog meter movements is the _____.
d'Arsonval movement
A meter that uses the taut band suspension and operates on very tiny amounts of current is often called a _____.
galvanometer
As the atmospheric pressure increases, the amount of voltage required to reach ionization potential _____.
increases
The nonconductive covering around a wire is the _____.
insulation
A(n) _____ must NEVER be connected to a circuit when the circuit power is turned on.
ohmmeter
Voltage _____ can be determined by observing the direction of current flow through the circuit.
polarity
The amount of _____ across a resistor is proportional to its resistance.
voltage drop
_____ provide(s) the magnetic field necessary for the operation of the machine.
a. Pole pieces
Several cells connected together are called a
battery
The _____ ride against the commutator segments and are used to connect the armature to the external circuit of the DC machine.
brushes
In an electroplating operation, the negative terminal is called the _____.
cathode
The low-impedance voltage tester is most suitable for use in _____.
high power circuits
As lead-acid batteries age, they may lose some of their capacity. To load test a battery, a load of three times the ampere-hour rating is connected to the battery. The voltage is monitored and after _____ minutes, the voltage should be above _____% of the rated voltage.
3 MIN, 80%
A two-resistor series circuit has an applied voltage of 100 V. The voltage across one of the resistors is 40 V. The voltage across the other resistor is _____.
60 V
The word _____ is often used in reference to a single cell.
Battery
In a parallel circuit, the current through each branch is inversely proportional to the resistance of the branch. Because of this, parallel circuits are sometimes called _____.
CURRENT DIVIDERS
Imagine a water system with a holding tank, pump, and return lines. What would happen to the resistance to flow if a return path is added to the system?
IT LESSENS
"The algebraic sum of the voltage sources and voltage drops in a closed circuit must equal zero" is _____.
Kirchhoff's voltage law
In a parallel circuit, the total current flow is equal to the _____ of the currents through all the branches.
SUM
Solar cells are constructed from a combination of P- and N-type _____ materials.
Semiconductor
Thermocouples produce voltage because of the action of two dissimilar metals. The voltage produced depends on the type of metals used and the _____ difference between the junction and the open ends.
Temperature
Circuit networks can be simplified down to an equivalent circuit, with a single voltage source and series resistor. This conversion is done in accordance with _____.
Thevenin's theorem
The output voltage of a generator is usually controlled by the amount of _____.
a. field excitation current
When the field winding of a DC motor is connected in parallel with the armature, the motor is called a _____ motor.
a. shunt
The speed regulation of a DC motor is proportional to the _____.
armature resistance
There are two conductors, a red and a blue installed in metallic conduit. You are using a MEGGER to test for grounds. How should the two leads of the MEGGER should be connected?
both a and b above
The motor that does not contain a wound armature, commutator, or brushes is the _____ motor.
c. brushless DC
A device that converts mechanical energy into DC electrical energy is a(n) _____.
c. generator
Each _____ of a battery produces a certain amount of voltage, depending on the material used to make it.
cell
A point that is used as a common connection for other parts of a circuit is called a _____ point.
chassis
A copper electroplating process sometimes uses a compound called _____.
copper sulfate
There are six current-carrying conductors in a raceway that is to be installed in an area with an ambient temperature of 90°F. It is necessary to _____.
correct for temperature and derate (because of the number of conductors)
The _____ effect occurs when the connection of a meter to the circuit changes the entire circuit operation.
loading
If a magnesium atom combines with two chlorine atoms, the result is _____.
metallic salt
A device that converts electrical energy into mechanical energy is called a(n) _____.
motor
A(n) _____ ammeter operates on more than one range by connecting the meter movement to different shunts.
multirange
There are two conductors, a red and a blue installed in metallic conduit. You are using a MEGGER to test for shorts. How should the two leads of the MEGGER should be connected?
one to the blue lead and one to the red lead
A cell which cannot be recharged is a _____ cell.
primary
Solving combination circuits includes a step in which you _____.
reduce the circuit to a simpler circuit
Once an arc is started in a gas, the voltage required to maintain conduction is _____.
reduced
The Wheatstone bridge is used to measure _____.
resistance
The longer the conductor, the more _____ it will have.
resistance
The servomotor which has a fiberglass and copper rotor is the _____ motor.
servodisc
In the National Electrical Code®, the current carrying abilities of conductors are called the _____.
ampacities
The most common type of ohmmeter is the series type. On an analog series ohmmeter scale, zero is on the _____.
right
An ammeter _____ is a low-resistance device used to conduct most circuit current away from the meter movement.
shunt
The total amount of resistance to current flow in a series circuit is equal to the _____ of the resistance in that circuit.
sum
The ambient air temperature considered in relation to a conductor ampacity is the temperature of the _____.
surrounding air
The current in any branch of a circuit supplied by a multipower source can be determined by finding the current produced in that particular branch by each of the individual power sources acting alone. This simplification is done in accordance with _____.
the superposition theorem
If there are more than _____ conductors in a raceway, the ampacity of the conductors must be derated.
three
In a combination circuit, to identify series and parallel elements, you should _____.
trace the current path(s)
The meter that measures true power in a circuit is the _____.
wattmeter
