DC Theory LMS
Determine the total resistance in a circuit where the power dissipated is 25 watts and the supplied voltage is 50 volts.
100 ohms
How much power is consumed in a circuit when the current is 12 amps and the voltage is 92 volts?
1104 W
Determine how much power is consumed in a circuit when the resistance is 30 ohms and the applied voltage is 60 volts.
120 W
How much power is consumed in a circuit when the resistance is 22 ohms and the applied voltage is 58 volts? (Round the final answer to one decimal place.)
152.91 W
Determine the total voltage in a circuit when the current is 5 amps and the resistance is 45 ohms.
225 V
Determine how much power is consumed in a circuit when the current is 9 amps and the applied voltage is 27 volts.
243 W
What would the total current in a circuit be if the applied voltage is 80 volts and the resistance is 20 ohms?
4 A
Facility procedures and manufacturer requirements must always be followed when using test instruments; in addition, ? must also be followed. (Select all that apply) a. application requirements b. NFPA 70E c. OSHA d. the NEC
A. B. C.
Which of the following is a basic rule that applies to a series circuit? (Select all that apply.) Select one or more: a. The current is the same wherever it is measured in the circuit. b. The total current is added for each circuit component. c. The total power is the sum of the individual circuit watt dissipations. d. The total resistance of the circuit is the sum of all the individual resistor values. e. The total voltage of the circuit is the sum of all the component voltage values in the circuit.
A. C. D. E.
Select all the correct formulas that may be used to find power in an electrical circuit. a. P= E/I b. P= E(2)/ I c. P= E(2)/ I d. P = I × E e. P = I2 × E f. P = I2 × R
C. D. E.
What is the formula which defines the voltage drop across a load in an electrical circuit?
EN = IT × RN
Which electrical formula should be used to find the wattage produced by a resistor if the resistor's resistance and current are known?
P = I(2) × R
The correct formula for determining the total power consumption of the circuit when E (volts) and I (amps) are known is ? . a. PT = ET × IT b. PT = ET2 × IT c. Pt = Et/ It d. PT = IT2 × RT
PT = ET × IT
Identify the statement(s) that is/are true to the laws of magnetism. (Select all that apply.) Select one or more: a. Energy is required to create a magnet (magnetic field), but no energy is required to maintain a magnet (magnetic field). b. Like poles repel each other, and unlike poles attract each other. c. The magnetic force between two poles is directly proportional to the pole strength and inversely proportional to the square of the distance between them. d. The magnetic force between two poles is inversely proportional to the pole strength and directly proportional to the square of the distance between them.
a. Energy is required to create a magnet (magnetic field), but no energy is required to maintain a magnet (magnetic field). b. Like poles repel each other, and unlike poles attract each other. c. The magnetic force between two poles is directly proportional to the pole strength and inversely proportional to the square of the distance between them.
The mathematical equation 0 = ΣIin − Σ(Iout) shows the relationship expressed in ? . a. Kirchhoff's Current Law b. Kirchhoff's Voltage Law c. the Law of Proportionality d. Ohm's Law
a. Kirchhoff's Current Law
One way to calculate the total power in a series circuit is to ? the component wattages. Select one: a. add b. divide c. multiply d. subtract
a. add
In a parallel circuit, the total current is determined by the component currents being ? . a. added b. divided c. multiplied d. subtracted
a. added
When resistors are connected in series, their values are ? to find the total circuit resistance. Select one: a. added b. divided c. multiplied d. subtracted
a. added
The formula PT = ET × IT determines the total power consumption of the circuit when ? and ? are known. a. amps / volts b. amps / watts c. volts / watts d. watts / ohms
a. amps / volts
The entire ? is dropped across each load in a parallel circuit. a. applied voltage b. circuit current c. circuit power d. circuit resistance
a. applied voltage
Ferromagnetic materials are materials that ? . Select one: a. are easily magnetized b. create opposition to the passage of flux lines c. create the magnetic force between two poles d. focus lines of flux
a. are easily magnetized
When current flows to the intended destination through the load and back to the source, it is said to be ? . Select one: a. complete b. grounded c. open d. short
a. complete
Circular mils are the units used to measure the ? . Select one: a. cross-sectional area of American conductors b. length of American conductors c. resistance of wire d. voltage drop of American conductors to and from the load
a. cross-sectional area of American conductors
A parallel circuit has multiple paths for ? to flow. a. current b. power c. resistance d. voltage
a. current
The water that is flowing through a pipe can be thought of as, and analogous to, electric ? . a. current b. power c. resistance d. voltage
a. current
Electromagnetic fields are formed by combining ? and ? . Select one: a. electrostatic fields / magnetic fields b. electrostatic fields / polar fields c. flux lines / poles d. magnetic fields / quantum fields
a. electrostatic fields / magnetic fields
If all resistors in a parallel circuit have the same value, then the total resistance is ? the value of any one of those resistors divided by the total number of all the resistors. a. equal to b. the product of c. the reciprocal of d. the sum of
a. equal to
The voltage applied to each load in a parallel circuit is ? the total voltage. a. equal to b. greater than c. half d. less than
a. equal to
Using the Principle of Superposition, the total current will be ? the sum of the individual currents. a. equal to b. half of c. less than d. more than
a. equal to
A DC generator creates a current that ? and an AC generator creates a current that ? . Select one: a. flows in 1 direction / flows in 2 directions b. flows in 2 directions / flows in 1 direction c. flows north to south / flows south to north d. flows south to north / flows north to south
a. flows in 1 direction / flows in 2 directions
The total power in a series circuit is equal to the sum of the ? by each resistor. Select one: a. power dissipated b. resistance dissipated c. voltage dissipated d. current dissipated
a. power dissipated
Regarding units of measurement, ? is to electrical potential as ? is to electrical current. a. volt / amp b. watt / volt c. watt / amp d. volt / watt
a. volt / amp
A typical solution to control a lighting load from two locations is to employ a pair of ? switches. a. 2-way b. 3-way c. 4-way d. single-pole
b. 3-way
The value 0.08 kilowatts can also be expressed as ? . a. 8 W b. 80 W c. 800 W d. 8,000 W
b. 80 W
In the United States, conductors are sized according to the ? standard. Select one: a. American National Standards Institute (ANSI) b. American Wire Gauge (AWG) c. National Electrical Code (NEC) d. National Wire Gauge (NWG)
b. American Wire Gauge (AWG)
What is the formula for finding total current in a parallel circuit when component currents are known? a. IT = I1 = I2 = I3 = ⋯ IN b. IT = I1 + I2 + I3 + ⋯ IN c. IT = I1 − I2 − I3 − ... IN d. IT = I1 × I2 × I3 × ...IN
b. IT = I1 + I2 + I3 + ⋯ IN
? states that any source can be reduced to an equivalent current source and an equivalent resistance. a. Kirchhoff's Law b. Norton's Theorem c. Principle of Superposition d. Thevenin's Theorem
b. Norton's Theorem
The ? can be determined using Ohm's Law and the ? any time there are components in series with the source. Select one: a. component current / parallel rules b. component voltage drops / total current c. total current / component wattage d. total resistance / component resistance
b. component voltage drops / total current
When working your way back up through your redraws, the ? can be determined using Ohm's Law because the ? for that group of components is the same when they are in series. Select one: a. component current / component voltage b. component voltages / component current c. total current / component wattage d. total resistance / component resistance
b. component voltages / component current
Electrical current, described as flowing from the positive terminal of a battery through the circuit and back to the negative side of the battery, is considered ? current flow. a. alternating b. conventional c. electron d. variable
b. conventional
Adding parallel loads to a circuit will ? total circuit resistance and ? the total circuit current. a. decrease / decrease b. decrease / increase c. increase / decrease d. increase / increase
b. decrease / increase
In an atom, ? have a negative charge, ? have a positive charge, and ? have no charge. a. electrons / neutrons / protons b. electrons / protons / neutrons c. neutrons / protons / electrons d. protons / electrons / neutrons
b. electrons / protons / neutrons
The ? a lamp's resistance, the ? a lamp's wattage. (Select all that apply.) a. higher / higher b. higher / lower c. lower / higher d. lower / lower
b. higher / lower c. lower / higher
If the voltage is increased in a circuit and all other components remain the same, the power consumed in the circuit will ? . a. decrease b. increase c. remain the same
b. increase
The motion of electrons in a conductor caused by the interaction between the magnetic field of the magnet and the magnetic field of the electrons causes a voltage to be ? . Select one: a. eliminated b. induced c. regulated d. sped up
b. induced
The flux lines of a magnet leave the ? pole and enter the ? pole. Select one: a. north / north b. north / south c. south / north d. south / south
b. north / south
In a circuit with an open switch, the current will ? . Select one: a. flow b. not flow c. slow down d. speed up
b. not flow
One ? is the amount of resistance in a circuit that allows one amp of current to flow when a potential of one volt is applied. a. amp b. ohm c. volt d. watt
b. ohm
A circuit where the voltage is the same across all components and equal to the supplied voltage is a ? circuit. Select one: a. complex b. parallel c. series d. series-parallel
b. parallel
In order to have voltage induced, there must be ? between the conductor and the magnetic field. Select one: a. electromagnetic induction b. relative motion c. reluctance d. resistance
b. relative motion
Combination or series-parallel circuits are circuits where ? . Select one: a. all components are connected in parallel b. some components are connected in series, while others are connected in parallel c. the current is split or follows two (or more) alternative paths d. the same current flows through all components
b. some components are connected in series, while others are connected in parallel
The formula E1 = Et x R1 / (R1 + R2) is known as ? . a. Kirchhoff's Law b. the Law of Proportionality c. Ohm's Law d. Watt's Law
b. the Law of Proportionality
According to the Laws of Proportionality, if a resistor in a parallel circuit has triple the resistance of a second resistor, it will have ? the current of the second resistor. a. 3/4 b. 1/2 c. 1/3 d. 1/4
c. 1/3
The value 200,000 ohms can also be expressed as ? . a. 2 kΩ b. 20 kΩ c. 200 kΩ d. 200 MΩ
c. 200 kΩ
According to the Law of Proportionality, if Resistor A in a series circuit has three times more resistance than Resistor B, then the voltage across Resistor A will have ? the voltage drop compared to Resistor B. a. 1/3 b. 2/3 c. 3 times d. the same as
c. 3 times
When controlling a load from three locations, a ? is used in conjunction with two ? . a. 3-way switch / 4-way switches b. 3-way switch / single-pole switches c. 4-way switch / 3-way switches d. 4-way switch / single-pole switches
c. 4-way switch / 3-way switches
What would create a stronger magnetic field? Select one: a. Increasing the number of loops in a coil b. Wrapping the windings of a conductor closer together c. Both a. and b. d. None of the above
c. Both a. and b.
? and ? are the two general types of resistors. a. Conductor / variable b. Fixed / conductor c. Fixed / variable d. Variable / adjustable
c. Fixed / variable
After breaking down the circuit and solving for the total equivalent resistance, using the given applied voltage, the total current can be calculated with ? ; then working back up through your redraws, the component current and voltage values can be determined. a. IT = I1 + I2 + I3 + ... IN b. IT = I1 = I2 = I3 = ... IN c. It = Et/ Rt d. It = Pt/ Et
c. It = Et/ Rt
dentify the type of circuit that would have no current flow through it. Select one: a. Complete b. Grounded c. Open d. Short
c. Open
Using Ohm's Law, what is the equation for total resistance when the total voltage and total current are known? Select one: a. Rt = It + Et b. Rt = It × Et c. Rt = Et/ It d. Rt = It/ Et
c. Rt = Et/ It
If the direction of the current flow changes, what else will change? Select one: a. The amount of resistance in the circuit b. The amount of voltage at the source c. The direction of the conductor passing through the flux lines d. The magnetic field of the electrons
c. The direction of the conductor passing through the flux lines
Common problems in electrical switches include all of the following except ? . Select one: a. connection issues b. connection points c. counterfeit devices d. switching systems
c. counterfeit devices
Other terms that are often used interchangeably with the term potential difference are voltage and ? . a. current b. electrolysis c. electromotive force d. electron flow
c. electromotive force
The variable letter "E" in Ohm's Law stands for ? , and is measured in ? . a. efficacy force / amps b. efficacy force / ohms c. electromotive force / volts d. electromotive force / watts
c. electromotive force / volts
Increasing the current flowing through a conductor will ? the strength of the electromagnetic field around that conductor. Select one: a. cause no change to b. decrease c. increase
c. increase
The attraction or repulsion that occurs when magnets are held close to each other is caused by ? flowing into and out of those magnets. Select one: a. currents b. magnetic domains c. magnetic lines of force d. magnetism
c. magnetic lines of force
When using Watt's Law to solve for the power dissipated in a circuit, the current is to be ? the voltage. a. added to b. divided by c. multiplied by d. subtracted from
c. multiplied by
The ohm is the measurement for the amount of ? that exists in a circuit object. a. current flow b. electromotive force c. opposition to current flow d. potential difference
c. opposition to current flow
When it becomes difficult to recognize which components of a circuit are in series and which are in parallel, it can be helpful to ? the circuit. Select one: a. guess the connections in b. measure c. redraw d. none of the above
c. redraw
Like poles of a magnet ? and unlike poles ? . Select one: a. attract / attract b. attract / repel c. repel / attract d. repel / repel
c. repel / attract
The equation RT = R1 + R2 + R3 + ... RNsolves for total ? in a series circuit. Select one: a. current b. power c. resistance d. voltage Feedback
c. resistance
Voltage can be increased in a DC generator by increasing the ? . a. AWG size of the conductor cutting the magnetic field b. resistance of the magnetic field c. speed of the relative motion between the conductor and the magnetic field d. time it takes for the armature to complete a full rotation Feedback
c. speed of the relative motion between the conductor and the magnetic field
A mechanical device designed to allow or interrupt current flow in a circuit is called a ? . Select one: a. fuse b. load c. switch d. timer
c. switch
In a series circuit, the current measured on the supply side of the load is ? the current measured on the return path from the load. Select one: a. greater than b. less than c. the same as d. none of the above
c. the same as
A series circuit is a circuit where ? . Select one: a. the current is split or follows two (or more) alternative paths, and all components have the same voltage dropped across them b. the current is split or follows two (or more) alternative paths, and the sum of the voltage drops adds up to the source voltage c. the same current flows through all components, and the sum of the voltage drops adds up to the source voltage d. the same current flows through all components, and their voltage drops are all equal to the source voltage
c. the same current flows through all components, and the sum of the voltage drops adds up to the source voltage
To determine when components in a circuit are in series or parallel, one should ? . Select one: a. calculate the current b. measure the resistance c. trace the current path(s) d. trace the voltage path(s)
c. trace the current path(s)
The formula EN = IT × RN is used to solve for the ? in a series electrical circuit. a. current frequency b. power surge c. voltage drop d. wattage
c. voltage drop
Is Cole an absolute piece of shit? a. yes b. maybe c. no, not at all
d. ****kkkkkkkk yeah he is, mother ****er can suck my balls
What does the formula R= K x L/ A calculate? Select one: a. Area of wires or conductors b. Current flow c. Load value d. Resistance of a wire or conductor
d. Resistance of a wire or conductor
In a series circuit, what two things are directly proportional? a. The current across the load AND the value of the resistance of that load b. The current across the load AND the voltage across the load c. The value of the current of the load AND the wattage across that load d. The voltage across the load AND the value of the resistance of that load
d. The voltage across the load AND the value of the resistance of that load
? states that any source can be reduced to a single equivalent voltage and an equivalent resistance in series. a. Kirchhoff's Law b. Norton's Theorem c. Principle of Superposition d. Thevenin's Theorem
d. Thevenin's Theorem
Which type of fixed resistor can withstand more heat than any other type of resistor? Select one: a. Composition carbon resistor b. Metal film resistor c. Metal glaze resistor d. Wire-wound resistor
d. Wire-wound resistor
In a parallel circuit, the current through any resistor is ? to the value of that resistor. a. added b. directly proportional c. equal d. inversely proportional
d. inversely proportional
The variable letter "P" in Watt's Law stands for ? , and is measured in ? . a. potential / volts b. potential / watts c. power / volts d. power / watts
d. power / watts
In an atom, ? have a positive charge, ? have a negative charge, and ? have no charge. a. electrons / neutrons / protons b. electrons / protons / neutrons c. neutrons / protons / electrons d. protons / electrons / neutrons
d. protons / electrons / neutrons
Abbreviated with the capital letter K or the Greek letter ρ (rho), specific resistance is also called ? . Select one: a. inductance b. load value c. ohms d. resistivity
d. resistivity
When current returns to the source without flowing through the load, it is referred to as a(n) ? . Select one: a. closed b. incomplete c. open d. short
d. short
The "Assumed Voltage" formula is used when the ? is not known and can be used to solve for the actual resistance total of the circuit. a. source or branch current b. source or branch power c. source or branch resistance d. source or branch voltage
d. source or branch voltage
Increasing the number of loops in a coil will increase the ? of the magnetic field. Select one: a. current b. resistance c. size d. strength
d. strength
In a series circuit, the ? of all the voltages dropped across all of the circuit components is equal to the source voltage. Select one: a. difference b. product c. quotient d. sum
d. sum
In a series circuit, total voltage is the ? . Select one: a. product of all the component voltages b. same as all component voltages c. sum of all the component resistances d. sum of all the component voltages
d. sum of all the component voltages
A series circuit is a circuit where ? . Select one: a. the current flows from a negative charge to a positive charge b. there are both parallel and series connected components c. there is more than one possible path for current to flow d. there is only one path for the current to flow
d. there is only one path for the current to flow
The number of actions that allow a switch to be closed is referred to as the ? of the switch. Select one: a. coils b. poles c. relay d. throws
d. throws
The current that leaves and re-enters a single power source in a parallel circuit is called the ? . a. branch current b. load current c. parallel current d. total current
d. total current
After thinking through the consolidation steps and redrawing the circuit to an equivalent resistor, the first step to solving a combination circuit is to calculate the ? . Select one: a. component power consumed b. component voltage drops c. total current flow d. total resistance
d. total resistance
A resistor with a movable contact that is adjusted by turning a shaft or stem is called a(n) ? resistor. Select one: a. adjustable b. fixed c. tapped d. variable
d. variable
Normal switch ratings on a switch include the values of the maximum current and the maximum ? . Select one: a. load b. power c. resistance d. voltage
d. voltage
Lamps will have ratings for both ? and ? . a. current / resistance b. resistance / voltage c. voltage / current d. voltage / power
d. voltage / power
A meter constructed for a typical residential application may not be fit for use in an industrial one. If the meter is not used for its proper application, possible outcomes include damage to ? . a. equipment b. persons c. property d. the meter e. all of the above
e. all of the above
