Final Exam Chapter 3
What is the voltage drop of each conductor of a 4-wire multiwire circuit? Each conductor is 12AWG, 100 ft in length, supplying a 16A load. The resistance of 12AWG conductors is 2ohms per 1,000 ft.
3.20V
Multiwire branch circuits have more conductors for a given number of circuits, which require the use of a larger raceway.
false
When power supplies are connected in series, the circuit voltage remains the same as when only one power supple is connected to it, provided that all the polarities are connected properly.
false
Because of the dangers associated with an open neutral conductor, the continuity of the _____ conductor cannot be dependent upon the receptacle.
grounded
Kirchoff's Current Law states, "In a series circuit, the current is ____________ through the transformer, the conductors, and the appliance."
the same
A balanced multiwire branch circuit will have the current flow only on the ungrounded conductors.
true
A multiwire circuit has two or more ungrounded conductors having a potential difference between them, and having an equal difference of potential between each ungrounded conductor and the neutral conductor.
true
A series is a circuit in which a specific amount of current leaves the voltage source and flows through every electrical device in a single path before it returns to the voltage source.
true
According to Kirchoff's Current Law, the total current provided by the source to a parallel circuit will equal the sum of the currents of all of the branches.
true
If the current in each ungrounded conductor of a multiwire circuit is the same, the grounded conductor carries 0A.
true
If the ungrounded conductors of a multiwire circuit are not terminated to different phases, this can cause the neutral current to be in excess of the neutral conductor rating.
true
Kirchoff's Voltage Law states, "In a series, circuit, the sum of the voltage drops across all of the resistors will equal to the applied voltage."
true
No matter how many resistances there are in a series circuit, the sum of the voltages across all of the resistances equal the voltage of the source according to the Law of Proportion.
true
Resistance opposes the flow of electrons. In a series circuit, the total circuit resistance is equal to the sum of all the resistance in series.
true
That portion of the series-parallel circuit that contains resistances in parallel comply with the rules for the parallel circuit.
true
That portion of the series-parallel circuit that contains resistances in series must comply with the rules for series circuits.
true
The advantage of the reciprocal method is that the formula can be used for as many resistances as the parallel circuit contains.
true
The current flowing on the neutral conductor of a multi-wire circuit is called "unbalanced current."
true
The current of the circuit can be determined by the formula I=Elittles/Rlittlet
true
When working with series-parallel circuits, it is best to redraw the circuit so you can see the series components and the parallel branches.
true
The neutral conductor of a 3-wire, 120/240V, single-phase circuit only carries current when the current on the ungrounded conductors is not identical.
true
The neutral conductor of a 3-wire, 120/240V, single-phase circuit will only carry the unbalanced current when the circuit is not balanced.
true
The opposition to current flow results in a voltage drop of the circuit voltage.
true
To determine the resistance of each resistive element in the circuit, use the formula R=Esquared/P. E is the rated voltage of the resistor, and P is the rated power of the resistor.
true
When power supplies are connected in parallel, the voltage remains the same, but the current or amp-hour capacity will be increased.
true
The product-over-sum method is used to calculate the resistance of _____________ resistance(s) at a time.
two
What is the voltage drop of two 12AWG conductors, each 100ft in length, supplying a 2-wire, 16A load? The resistance of 12AWG conductors is 2ohms per 1,000 ft.
6.40V
A balanced 3-wire, 120/240V single-phase circuit is connected so that the ungrounded conductors are from different transformer phases (Line 1 and Line 2.) The current on the neutral conductor will be __________ percent of the ungrounded conductor current.
0
The total resistance of a parallel circuit can be calculated by the ___________ method.
equal resistance, product-over-sum, reciprocal (any of these.)
According to the equal resistance method, when all the resistances of the parallel circuit have the same resistance, divide the resistance of one element by the largest resistor in parallel.
false
In a parallel circuit, the total circuit resistance is always greater than the smallest resistance.
false
In a parallel circuit, the voltage drop across each resistance is equal to the sum of the voltage drops of each of the resistors in parallel.
false
Improper wiring on mishandling of multiwire branch circuits can cause ________________ connected to the circuit.
overloading of the neutral conductors and destruction of equipment because of overvoltage (b and c)
A _________________ is a circuit that contains some resistances in series and some resistances in parallel with each other.
series-parallel circuit
For practical purposes, series circuits are often used for ______________ applications.
signal and control (a and b)
