Chapter 3 test

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 is _____ percent of the ungrounded conductor current.

0

The product-over-sum method is used to calculate the resistance of _____ resistance(s) at a time.

2

What is the voltage drop of each ungrounded conductor of a 4-wire multiwire circuit? Each conductor is 12 AWG, 100 ft in length, supplying a 16A load. The resistance of 12 AWG conductors is 2 ohms per 1,000 ft.

3.20

What is the voltage drop of two 12 AWG conductors, each 100 ft in length, supplying a 2-wire, 16A load? The resistance of 12 AWG conductors is 2 ohms per 1,000 ft.

6.40V

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

Multiwire branch circuits have more conductors for a given number of circuits, which requires 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 supply is connected to it, provided that all the polarities are connected properly.

False

A _____ is a circuit that contains some resistances in series and some resistances in parallel with each other.

Series-parrell circuit

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 has current flow only on the ungrounded conductors.

True

A multiwire circuit is a circuit consisting of two or more ungrounded conductors (hot wires) that have a voltage between them, and an equal voltage between each ungrounded conductor and the neutral conductor.

True

A series circuit 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 equals 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 exceed the grounded conductor rating.

True

Kirchoff's Voltage Law states, "In a series circuit, the sum of the voltage drops across all of the resistors equals 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 equals 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 of the resistances in series.

True

That portion of the series-parallel circuit that contains resistances in parallel must comply with the rules for parallel circuits.

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 multiwire circuit is called "unbalanced current."

True

The current of the circuit can be determined by the formula I = ES/RT.

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 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 = E2/P. E is the rated voltage of the resistor, and P is the rated power of the resistor.

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

Because of the dangers associated with an open neutral conductor, the continuity of the _____ conductor in a multiwire branch circuit cannot depend upon the receptacle.

none of these

Improper wiring or mishandling of multiwire circuits can cause _____ connected to the circuit.

overloading the neutrals destruction of the equipment

Series circuits are often used for _____ applications.

signal and control