AC/DC Final Exam Ch 17-19

False

In a parallel inductive-resistive-capacitive circuit, a leading current indicates an inductive circuit.

False

In a pure capacitive circuit, the capacitor uses energy to charge, and half of this energy is returned to the circuit when the capacitor discharges.

inductive

In a series circuit, if inductive reactance is larger than capacitive reactance, then the circuit is ____________________.

impedance

In a series inductive-resistive-capacitive circuit, circuit current is equal to source voltage divided by circuit ___.

False

In a series inductive-resistive-capacitive circuit, inductive and capacitive voltages are in phase with each other.

True

In a series resistive AC circuit, source voltage and line current are in phase with each other.

apparent power

In a series resistive-capacitive circuit, ____________________ leads current and source voltage, indicating capacitance.

False

In a series resistive-capacitive circuit, impedance is the combination of inductance and capacitive reactance to oppose the flow of voltage.

resistance

In a series resistive-capacitive circuit, only ____________________ can dissipate true power.

False

In a series resonant circuit, minimum power occurs at resonance.

voltage

In a series/parallel resistive-capacitive circuit, ___ is used as the reference point for the parallel branches.

current

In a series/parallel resistive-capacitive circuit, ___ is used as the reference point for the series components.

True

Power in a pure capacitive circuit is the equivalent of reactive power in a capacitive circuit.

voltage

Resistive branch circuit current is in phase with resistive branch circuit ____________________.

False

Series resonant circuits have low inductive voltages.

True

When a series circuit is capacitive, line current leads the source voltage.

cutoff

A ___ frequency is the half-power frequency point.

current

A change in capacitive reactance results in different capacitive ____________________ in each branch circuit of a parallel resistive-capacitive circuit.

False

A change in impedance also causes a change in capacitive reactance.

inductive-resistive-capacitive

A circuit where all inductive, resistive, and capacitive circuit elements are connected in one current path is known as a series ____________________ circuit.

True

A low-pass frequency filter blocks all frequencies above a selected frequency.

False

A parallel resonant circuit has an angle theta equal to 270°.

vector

A power ___ diagram is used to calculate apparent power in a parallel inductive-resistive-capacitive circuit.

True

A pure capacitive circuit is theoretical because it involves no resistance.

False

A series resonant circuit attenuates AC at the resonant frequency and passes current at nonresonant frequencies.

False

Adding capacitance to an AC series circuit increases the circuit current.

resistance

An impedance vector diagram indicates that, at resonance, inductive reactance and capacitive reactance cancel, and total impedance is equal to total ___.

True

Angle theta is the angle by which current leads the source voltage.

impedance

Dividing source voltage by the total circuit current yields ____________________.

True

Excessive voltage in a series resonant circuit can damage components.

False

Frequency does not affect capacitive reactance.

True

Frequency must be known in order to calculate inductive reactance.

0.707

Half power in a series resonant circuit occurs when the resistive current and voltage have been reduced to ___ of their maximum values at resonance.

cosine

If angle theta is known, the ___ function can be used to calculate the value of the source voltage.

capacitive reactance

If frequency is changed in a series resistive-capacitive circuit, the only parameter directly affected is ____________________.

resistance

Impedance in a series resonant circuit is equal to the vector sums of reactance and ___.

90

In a capacitive circuit, circuit current leads the source voltage by ____________________°.

True

In a capacitor, consumed power has a positive value, while power returned to a circuit is negative.

True

In a parallel inductive-resistive-capacitive circuit, the power factor is equal to the true power divided by the apparent power.

resistance

In a parallel resistive-capacitive circuit, frequency has no effect on source voltage or ___.

90

In a pure capacitive circuit, current leads the source voltage by ___°.

True

In a simple series circuit, current is the reference point.

series/parallel resistive-capacitive

In a(n) ____________________ circuit, resistive voltage drop is in phase with current (IR) while capacitive voltage drop lags current (IC) by 90°.

True

In an inductive-resistive circuit, apparent power is lagging, indicating inductance.

voltage drop

In any series resistive-capacitive circuit, the resistive current and the ____________________ across the resistor are in phase.

capacitance

Increasing the amount of ____________________ in series resistive-capacitive circuits reduces the amount of capacitive reactance.

False

Increasing the frequency in a parallel inductive-resistive-capacitive circuit causes current flow to increase in the inductive branch.

False

Inductive and capacitive branches of a circuit have no resistance.

impedance

Ohm's law is used to calculate ____________________ by dividing the source voltage by the total circuit current.

True

Parallel resistive-capacitive circuits are used in electronic AC applications such as computers, CD-ROM players, DVD players, DVR equipment, amplifiers, stereo receivers, oscilloscopes, and video production equipment.

180

Reactive power values are ___° out of phase.

True

Resistive current is in phase with source voltage in a parallel resistive-capacitive circuit.

reactance

Resonance is the condition where the inductive ___ equals capacitive reactance at a given frequency.

frequency

Series/parallel inductive-resistive-capacitive circuits are usually analyzed to calculate all of the following except ___.

False

Series/parallel resistive-capacitive circuits should not be used for electronics applications.

180

Since an inductive reactance and a capacitive reactance are ___° out of phase with each other, they can be added together.

True

Some low-pass filters are designed to use a capacitor.

True

The Pythagorean theorem can be used to calculate the source current in a parallel resistive-capacitive circuit.

apparent power

The ___ in a parallel inductive-resistive-capacitive circuit is equal to the line current multiplied by the source voltage.

quality factor

The ___ of a parallel resonant circuit is the ratio of the tank current to the total current.

True

The angle theta of a series resonant circuit is equal to 0°.

True

The characteristics of a frequency filter make it possible to select a broadcast from one radio station while excluding others.

True

The resistive branch circuit only opposes current flow.

Pythagorean theorem

The vector diagram calculation method or the ____________________ can be used to calculate total current in a series/parallel inductive-resistive-capacitive circuit.

True

Total circuit impedance in a parallel resonant circuit can be calculated when source voltage and total current are known.

False

Total reactive power can be calculated by subtracting the inductive power vector from the capacitive power vector.

True

Voltage is not measured in a parallel resonant circuit because it is typically known.

False

When a load is a series resistive-capacitive combination, current flow is initially at its minimum value.

True

When a resistance is added to a tank circuit, the sine wave oscillations become damped and eventually cease.

True

When a series circuit is inductive, the current lags the source voltage.

current

When analyzing a series circuit, ___ is used as a reference for all other circuit parameters.

True

When analyzing parallel inductive-resistive-capacitive circuits, it is assumed that each branch is purely inductive, capacitive, or resistive.

capacitive reactance

When frequency is changed, the only parameter directly affected is the ___, while the other parameters are indirectly affected by the change.

False

When the reactive and resistive values of components are given, impedance in a parallel resistive-capacitive circuit can be calculated by using the vector diagram method.

False

When the values of circuit resistance and capacitive reactance are known, total impedance in a series resistive-capacitive circuit can be calculated by using Ohm's law.

apparent power

When the values of source voltage and total current are known, ___ in a series resistive-capacitive circuit can be calculated by multiplying the voltage and current.

False

When the voltage and the values of inductance and capacitance are known, the inductive and capacitive reactance can be calculated.

reactance

With an inductive or capacitive circuit, inductance and capacitance present an opposition to current flow known as ____________________.

source voltage

Without taking any measurements, values that are typically known in a parallel inductive-resistive-capacitive circuit are the ___ and component values.

Power factor

___ in a parallel resonant circuit is equal to the cosine of angle theta.

Power

___ in series resonant circuits can be used to indicate whether the circuit is at resonance.

Attenuation

___ is a reduction in the strength of a frequency signal.

Bandwidth

___ is the range of frequencies that the circuit passes without a significant reduction in the signal magnitude.

Voltage

___ is the same across all branch circuits of a parallel inductive-resistive-capacitive circuit.

Current

___ is the same throughout the circuit of a series inductive-resistive-capacitive circuit.

Capacitive

___ reactance is the opposition to current flow by a capacitor.

Angle theta

____________________ is calculated by calculating the voltage ratio value and then determining the angle for which the tangent ratio is valid.

Source voltage

____________________ is directly across the capacitive load.

Voltage

____________________ is the same across all components connected in parallel in resistive-capacitive circuits.

True

Current is often reduced to its vertical and horizontal components in order to calculate total line current.

False

Current is used as the reference in a parallel inductive-resistive-capacitive circuit.

True

As capacitive reactance increases, circuit impedance increases.

True

At reject frequencies, a capacitor presents a high reactance to the source, limiting the current flow through the load.

True

At resonant frequency, a series resonant circuit is neither capacitive nor inductive.

True

Band-pass filters are usually used in communications applications to tune frequency bands.

False

Band-reject frequency filters increase signals between selected frequencies.

inversely

Capacitive reactance is ____________________ proportional to frequency.

True

Capacitive reactance is inversely proportional to frequency (in Hz) and capacitance (in F).

source

Capacitive voltage is equal to the ____________________ voltage at all times in a closed-loop circuit.

True

Changes in circuit parameters in both series and parallel resistive-capacitive circuits vary with an increase or decrease in frequency or capacitance.