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.