unit 23
What is defined as a dramatic increase in voltage lasting 2 nanoseconds or less?
voltage spike
When calculating resonant frequency, in what units is inductance measured?
Henrys
In an RLC series circuit, _____ is the same through all components and the _____ are out of phase.
current; voltages
Because inductive and reactance and capacitive reactance are 180° out of phase with each other in an RLC series circuit, mathematical addition must be used to find their sum.
false
When calculating resonant frequency, in what units is capacitance measured?
farads
Voltage spikes and surges can travel to electrical equipment via what?
ground connection
If the applied voltage of an MOV is below its voltage rating, it exhibits a very __________ resistance.
high
When calculating resonant frequency, what does the value L represent?
indutance
What has its primary and secondary winding physically and electrically separated from each other?
isolation transformer
If an RLC parallel circuit contains more capacitive VARs than inductive VARs, the circuit has a _____ power factor.
leading
What is used to describe the amount of interference caused by an unwanted signal?
noise-to-signal ratio
When determining bandwidth, what does Q represent?
quality of bandwidth
When calculating values in an RLC parallel circuit, what does VARSC represent?
reactive power of the capacitor
What type of circuits are used to provide great increases of current and voltage at the resonant frequency?
resonant
Because inductive reactance and capacitive reactance are 180° degrees out of phase with each other, they __________from each other in an AC circuit
subtract
Capacitive reactance is measured in ohms.
true
In an RLC parallel circuit, the phase angle difference between the applied voltage and the total current is determined by the ratio of resistance, inductance, and capacitance connected in parallel.
true
Subtraction of the inductive reactance and capacitive reactance in an RLC series circuit, permits the impedance of the circuit to become less than either or both of the reactances.
true
The current flowing through a pure resistive element in an RLC parallel circuit will be in phase with the applied voltage.
true
When using vector addition for inductive reactance and capacitive reactance, the larger value is reduced by the amount of the smaller value.
true
When using vector addition for inductive reactance and capacitive reactance, the smaller value is eliminated.
true
If the power factor is corrected exactly so that the circuit is purely resistive, the power factor has a value of _____.
unity
In an RLC series circuit, the ratio of resistance, inductance, and capacitance determines how much the applied _____ leads or lags the circuit current.
voltage
In an RLC parallel circuit, the _____ is the same through all components and the _____ are out of phase.
voltage; currents
Because inductive reactance and capacitive reactance are _____ out of phase with each other, they subtract from each other in an AC circuit.
180 degrees
When power is applied to a capacitor, it begins to charge to the peak value of the ________.
appilied voltage
To correct the power factor to 100%, an equal amount of capacitive VARs would be connected in _____ with the motor.
parallel
When calculating values in an RLC parallel circuit, what does IL represent?
current flow through the inductor
During the period of time that the circuit is not at resonance, what is limited by the combination of inductive reactance and capacitive reactance?
current
As current increases, a magnetic field _________ around the inductor, inducing a voltage into the coil.
expands
Current can rise instantly through an inductor.
false
When determining bandwidth, what components result in a sharp increase and decrease of current?
high-Q components
If an RLC series circuit contains more capacitive VARs than inductive VARs, then the circuit has a _____ power factor.
leading
If the current leads the voltage in an RLC series circuit, the power factor is referred to as _____.
leading
What are designed to protect against much higher voltages and currents, such as lightning strikes?
lightning arresters
Capacitors help reduce or eliminate voltage spikes and surges by the current- limiting effect of a capacitor beingaffected by the frequency.
true
The impedance of the RLC series circuit is the sum of resistance, inductive reactance, and capacitive reactance.
true
When values of inductive reactance and capacitive reactance become equal, they are said to be resonant.
true
IR represents current flow through the inductor.
false
The current flowing through a pure inductive element leads the applied voltage by 90 electrical degrees.
false
When Ohm's law is applied to the RLC series circuit values, the voltage drops developed across the inductor or capacitor can be lower than the applied voltage.
false
If an RLC series circuit contains more inductive VARs than capacitive VARs, the circuit has a _____ power factor.
lagging