Delmar 8
Capacitors oppose a change of voltage. True False
True
If an RLC series circuit contains more capacitive VARs than inductive VARs, then the circuit has a _____ power factor. lagging leading
leading
If the power factor is corrected exactly so that the circuit is purely resistive, the power factor has a value of _____. zero 0.95 50% unity
unity
An RLC series circuit is powered by a 120-V, 60-Hz supply. It contains an inductor that has an inductive reactance of 50 Ω and a wire resistance of 10 Ω. What is the inductance of the inductor? 0.0265 H 0.133 H 0.259 H 0.335 H
0.133 H
An RLC series circuit has a 60-Hz, 120V applied voltage. R = 50 Ω, XL = 137 Ω, and XC = 160 Ω. What is the inductance in the circuit? 0.133 H 0.261 H 0.363 H 0.424 H
0.363 H
An RLC series circuit has an applied voltage of 240 volts. R = 48 Ω, XL = 100 Ω, XC = 36 Ω, and Z = 80 Ω. What is the voltage drop across the capacitor? 40 V 108 V 300 V 444 V
108 V
An RLC parallel circuit has an applied voltage of 240 V. R = 60 Ω, XL = 80 Ω, and XC = 40 Ω. What is the apparent power? 300 VA 1200 VA 1400 VA 1440 VA
1200 VA
An RLC series circuit has an applied voltage of 240 volts. R = 51 Ω, XL = 100 Ω, and XC = 32 Ω. The voltage drop across the inductor is 282 V. What is the voltage drop on the resistor? 143.82 V 192.73 V 382.5 V 422.4 V
143.82 V
What is the typical capacitance rating of a typical MOV? 6500 A 70 joules 1900 pf 1 W
1900 pf
An RLC series circuit has an applied voltage of 240 volts. R = 48 Ω, XL = 100 Ω, XC = 36 Ω, and Z = 80 Ω. What is the total current? 1 A 2 A 3 A 4 A
3 A
An RLC series circuit has an applied voltage of 240 volts. R = 48 Ω, XL = 100 Ω, XC = 36 Ω, and Z = 80 Ω. What is the reactive power of the capacitor? 100 VARs 208 VARs 324 VARs 520 VARs
324 VARs
An RLC parallel circuit has an applied voltage of 240 volts. R = 60 Ω, XL = 100 Ω, and XC = 32 Ω. What is the resistive current? 3.5 A 4 A 5.4 A 6 A
4 A
An RLC series circuit is powered by a 120-V, 60-Hz supply. It contains a capacitor that has an XL of 50 Ω. What is the capacitance of the capacitor? 53.05 μF 106.1 μF 132.63 mF 265.25 mF
53.05 μF
An RLC series circuit has R = 42 Ω, XL = 80 Ω, and XC = 24 Ω. What is angle theta? 36.87° 53.13° 59.74° 62.33°
53.13°
An RLC parallel circuit has an applied voltage of 240 volts. R = 48 Ω, XL = 100 Ω, and XC = 36 Ω. What is the total current? 6.57 A 7 A 8.4 A
6.57 A
An RLC parallel circuit has an applied voltage of 240 volts. R = 48 Ω, XL = 100 Ω, and XC = 36 Ω. What is the circuit impedance (Z)? 25.49 Ω 43 Ω 59 Ω 62.17 Ω
62.17 Ω
A parallel tank circuit operating at its resonant frequency has an impedance of 10,000 Ω. At the points on either side of the resonant frequency that define the bandwidth, the impedance is approximately _____. 6,000 Ω 7,070 Ω 10,140 Ω 15,000 Ω
7,070 Ω
An RLC series circuit has an applied voltage of 240 volts. R = 48 Ω, XL = 100 Ω, XC = 36 Ω, and Z = 80 Ω. What is the reactive power of the inductor? 644 VARs 720 VARs 808 VARs 900 VARs
900 VARs
An RLC series circuit has an applied voltage of 277 volts. The current through the resistor is 3.5 A. What is the apparent power of the circuit? 210.92 VA 220.61 VA 790.14 VA 969.5 VA
969.5 VA
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. True False
False
Current can rise instantly through an inductor. True False
False
IR represents current flow through an inductor True False
False
Inductors cannot be used to reduce current spikes and surges. True False
False
The current flowing through a pure capacitive element will lag the voltage by 90 electrical degrees. True False
False
The current flowing through a pure inductive element leads the applied voltage by 90 electrical degrees. True False
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. True False
False
LC parallel circuits are often referred to as _______________ circuits.
Tank
Capacitive reactance is measured in ohms. True False
True
Capacitors help reduce or eliminate voltage spikes and surges by the current- limiting effect of a capacitor being affected by the frequency. True False
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 False
True
In an RLC series circuit, as frequency increases, inductive reactance increases and capacitive reactance decreases. True False
True
One joule is the amount of energy expended in applying a force of one Newton through a distance of one meter. True False
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 False
True
The current flowing through a pure resistive element in an RLC parallel circuit will be in phase with the applied voltage. True False
True
The impedance of an RLC parallel circuit is the reciprocal of the sum of the reciprocals of the legs. True False
True
The impedance of the RLC series circuit is the sum of resistance, inductive reactance, and capacitive reactance. True False
True
Thermal fuses are sensitive to heat instead of current. True False
True
When using vector addition for inductive reactance and capacitive reactance, the larger value is reduced by the amount of the smaller value. True False
True
When using vector addition for inductive reactance and capacitive reactance, the smaller value is eliminated. True False
True
When values of inductive reactance and capacitive reactance become equal, they are said to be resonant. True False
True
When power is applied to a capacitor, it begins to charge to the peak value of the ________. total voltage induced voltage applied voltage voltage drop
applied voltage
In a parallel LC circuit, the difference in frequencies above and below resonance at which impedance is 0.707 of the maximum is called the _____ of the circuit. bandwidth bandpass resonance Q
bandwidth
What are typically used to help eliminate voltage spikes and surges? rods insulators capacitors inductors
capacitors
The amount of voltage induced in the coil is proportional to the rate of ____________. applied voltage change of current induced voltage change of voltage
change of current
During the period of time that the circuit is not at resonance, what is limited by the combination of inductive reactance and capacitive reactance? resistance frequency current flow current circuit
current flow
In an RLC series circuit, _____ is the same through all components and the _____ are out of phase. voltage; currents current; voltages
current; voltages
As current increases, a magnetic field _________ around the inductor, inducing a voltage into the coil. charges compresses expands constricts
expands
What can be determined when the values of inductance and capacitance are known? frequency of resonance bandwidth resistive current resistance
frequency of resonance
When calculating resonant frequency, what does the value L represent? frequency at resonance inductance capacitance impedance
inductance
If an RLC parallel circuit contains more inductive VARs than capacitive VARs, the circuit has a _____ power factor. lagging leading
lagging
If an RLC series circuit contains more inductive VARs than capacitive VARs, the circuit has a _____ power factor. lagging leading
lagging
If the voltage in an RLC series circuit is ahead of the current, the power factor is referred to as _____. lagging leading
lagging
If an RLC parallel circuit contains more capacitive VARs than inductive VARs, the circuit has a _____ power factor. lagging leading
leading
If the current leads the voltage in an RLC series circuit, the power factor is referred to as _____. lagging leading
leading
If the voltage is behind the current in an RLC series circuit, the power factor is referred to as _____. lagging leading
leading
In an RLC series circuit, the point at which XL and XC are equal is called _____. equality resonance inductance bandwidth
resonance
Because inductive reactance and capacitive reactance are 180° degrees out of phase with each other, they __________ from each other in an AC circuit. add subtract multiply divide
subtract
When an AC circuit contains elements of resistance, inductance, and capacitance connected in parallel, what is the voltage dropped across each element? the same greater than true power less than true power equal to applied voltage
the same