50) The current through a 50-Ω resistor is I = (0.80 A) sin(240t), where t is measured in seconds.
How much power on average is dissipated in the resistor?
A) 16 W
B) 32 W
C) 45 W
D) 64 W
51) At what frequency does a 10-μF capacitor have a reactance of 0.12 kΩ?
52) At what frequency will the inductive reactance of a 44-mH inductor be equal to the
capacitive reactance of a 27-pF capacitor?
53) A 0.10-μF capacitor is connected to a 120-V rms 60-Hz source.
(a) What is its capacitive reactance?
(b) What is the rms current to the capacitor?
(c) If both the capacitance and the frequency were doubled, what would be the rms current?
54) A 0.200-H inductor is connected to a 60.0-Hz 120-V rms source.
(a) What is the inductive reactance?
(b) What is the rms current to the inductor?
(c) If both the inductance and the frequency were doubled, what would be the rms current?
55) What capacitance will have the same reactance as a 100-mH inductance of both of them are
in a 120-V 60-Hz circuit?
56) In the circuit shown in the figure, the 60-Hz ac source has a voltage amplitude of 120 V, the
capacitive reactance is the inductive reactance is and the resistance is What is
the capacitance C of the capacitor?
A) 3.2 µF
B) 6.3 µF
C) 9.4 µF
D) 13 µF
E) 20 µF
57) The reactance of a capacitor is at a frequency of What is the capacitance?
A) 0.066 μF
B) 0.42 μF
C) 2.6 μF
D) 0.093 μF
58) A 6.0-μF capacitor is connected to an ac signal with a frequency of 60 Hz. If the maximum
voltage applied to the capacitor is 8.0 V, what is its capacitive reactance?
A) 6.0 Ω
B) 440 Ω
C) 7.5 × Ω
D) 740 Ω
E) 160 Ω
59) The capacitive reactance of a 44-μF capacitor in an ac circuit is 6.0 × Ω. What is the
frequency of the applied signal?
A) 80 Hz
B) 17 Hz
C) 800 Hz
D) 6.0 Hz
E) 2.2 Hz
60) A 120-V rms voltage is applied across a 6.0-μF capacitor. If the frequency of the generator is
60 Hz, what is the rms value of the current in the circuit?
A) 0.47 A
B) 0.37 A
C) 0.071 A
D) 0.17 A
E) 0.27 A
61) At what frequency does a 10-μF capacitor have a reactance of 1200 Ω?
A) 13 Hz
B) 42 Hz
C) 60 Hz
D) 83 Hz
62) At what frequency will the capacitive reactance of a 0.010-μF capacitor be 100 Ω?
A) 1.0 kHz
B) 16 kHz
C) 0.16 MHz
D) 0.31 MHz
63) What is the rms current through a 0.0010-μF capacitor at 1000 Hz and 5.0 V?
A) 5.4 μA
B) 31 μA
C) 3.1 mA
D) 10 mA
64) What is the reactance of a 20-mH inductor at a frequency of 60 Hz?
A) 7.5 Ω
B) 0.13 Ω
C) 1.2 Ω
D) 1.2 mΩ
E) 7.5 mΩ
65) At what frequency is the reactance of a 20.0-mH inductor equal to 120 Ω?
A) 318 Hz
B) 637 Hz
C) 796 Hz
D) 955 Hz
E) 1110 Hz
66) In the circuit shown in the figure, the 60-Hz ac source has a voltage amplitude of 120 V, the
capacitive reactance is the inductive reactance is and the resistance is What is
the inductance L of the inductor?
A) 770 mH
B) 1700 mH
C) 2900 mH
D) 3700 mH
E) 4800 mH
67) What is the reactance of a 1.0-mH inductor at 60 Hz?
A) 0.19 Ω
B) 0.38 Ω
C) 2.7 Ω
D) 5.3 Ω
68) What is the inductive reactance of a 2.50-mH coil at 1000 Hz?
A) 2500 Ω
B) 796 Ω
C) 15.7 Ω
D) 2.50 Ω
69) At what frequency will a 14.0-mH coil have 14.0 Ω of inductive reactance?
A) 1000 Hz
B) 505 Hz
C) 257 Hz
D) 159 Hz
70) The inductor in a radio receiver carries a current of amplitude 0.200 A when an ac voltage of
amplitude 2.40 V is across it at a frequency of 1400 Hz. What is the value of the inductance?
A) 1.43 mH
B) 1.36 mH
C) 9.20 mH
D) 4.42 mH
E) 1.97 mH
71) At what frequency will a 20.0-mH inductor have an inductive reactance of 100 Ω?
A) 225 Hz
B) 655 Hz
C) 796 Hz
D) 457 Hz
E) None of the other answers is correct.
72) What rms current flows in a 60-mH inductor when 120-V rms ac at a frequency of 20 kHz is
applied to it?
A) 8.0 mA
B) 16 mA
C) 24 mA
D) 32 mA
73) What is the rms current through a 2.50-mH coil due to a 110-V rms, 60-Hz source?
A) 0.94 A
B) 2.5 A
C) 104 A
D) 117 A
74) A 120-V rms signal at 60.0 Hz is applied across a series combination of a 30.0-mH inductor
and a resistor. If the rms value of the current in this circuit is 0.600 A, what is the resistance of
the resistor?
A) 80.0 Ω
B) 268 Ω
C) 143 Ω
D) 200 Ω
E) 30.0 Ω
75) A 120-V rms signal at 60 Hz is applied across a series combination of a 30-mH inductor and
a 100-Ω resistor. What is the rms value of the current in this circuit?
A) 0.80 A
B) 1.2 A
C) 1.4 A
D) 1.6 A
E) 1.8 A
76) A 120-V rms signal at 60 Hz is applied across a series combination of a 30-mH inductor and
a 100-Ω resistor. What is the rms value of the voltage across the resistor?
A) 120 V
B) 60 V
C) 100 V
D) 150 V
E) 0.70 V
77) A 120-V rms voltage is applied across a 6.0-μF capacitor and a series combination of a 100–
Ω resistor. If the frequency of the power source is 60 Hz, what is the rms value of the current in
the circuit?
A) 0.26 A
B) 0.36 A
C) 0.46 A
D) 0.56 A
E) 0.76 A
78) A 120-V rms voltage at 60 Hz is applied across a series combination of a 20-μF capacitor
and an unknown resistor. If the rms value of the current in the circuit is 0.60 A, what is the
resistance of the resistor?
A) 60 Ω
B) 120 Ω
C) 180 Ω
D) 150 Ω
E) 200 Ω
79) A 120-V rms signal at 60.0 Hz is applied across a series combination of a 30.0-mH inductor
and a 100-Ω resistor. What is the rms value of the voltage across the inductor?
A) 0.700 V
B) 119 V
C) 100 V
D) 13.5 V
E) 120 V
80) As shown in the figure, an ac source whose rms voltage is 80 V is in series with a 100-Ω
resistor and a capacitor whose reactance is 200 Ω at the frequency of the source. What is the rms
voltage across the capacitor?
A) 66 V
B) 68 V
C) 70 V
D) 72 V
E) 74 V
81) A 120-V rms voltage at 2000 Hz is applied to a 6.0-mH inductor, a 2.0-μF capacitor, and a
200-Ω resistor. What is the rms value of the current in this circuit?
A) 1.5 A
B) 0.48 A
C) 2.5 A
D) 3.5 A
E) 0.59 A
82) A 120-V rms voltage at 1000 Hz is applied to an inductor, a 2.00-μF capacitor and a 100–Ω
resistor. If the rms value of the current in this circuit is 0.680 A, what is the inductance of the
inductor?
A) 34.2 mH
B) 35.8 mH
C) 11.4 mH
D) 17.9 mH
E) 22.8 mH
83) A 120-V rms voltage at 1.0 kHz is applied to a 2.0-mH inductor, a 4.0-μF capacitor and a
resistor. If the rms value of the current in this circuit is 0.40 A, what is the value of the resistor?
A) 300 Ω
B) 95 Ω
C) 420 Ω
D) 120 Ω
E) 240 Ω
84) A series circuit has a sinusoidal voltage supplied to it at with a peak voltage of
It also contains a resistance, a capacitance, and a inductance. What is the peak
current for this circuit?
A) 6.3 μA
B) 11 μA
C) 26 μA
D) 30 μA
85) In the circuit shown in the figure, the 60-Hz ac source has a voltage amplitude of 120 V, the
capacitive reactance is the inductive reactance is and the resistance is What is
the rms current in the circuit?
A) 0.11 A
B) 0.13 A
C) 0.14 A
D) 0.17 A
E) 0.20 A
86) The figure shows a series ac circuit. The inductor has a reactance of 60 Ω and an inductance
of 150 mH. A 50-Ω R and a capacitor C whose reactance is 90 Ω are also in the circuit, and the
rms current in the circuit is 1.5 A. What is the rms voltage of the source?
A) 87 V
B) 84 V
C) 81 V
D) 78 V
E) 75 V
87) The figure shows a series ac circuit. The inductor has a reactance of 80 Ω and an inductance
of 220 mH. A 30-Ω resistor and a capacitor whose reactance is 80 Ω are also in the circuit, and
the rms current in the circuit is 2.0 A. What is the capacitance of the capacitor?
A) 34 μF
B) 37 μF
C) 32 μF
D) 30 μF
E) 27 μF
88) The figure shows a series ac circuit. The inductor has a reactance of 50 Ω and an inductance
of 220 mH. An 80-Ω resistor and a capacitor whose reactance is 160 Ω are also in the circuit, and
the rms current in the circuit is 2.2 A. What is the voltage amplitude across the capacitor?
A) 500 V
B) 350 V
C) 630 V
D) 770 V
E) 210 V
89) A series circuit has a 50-Hz ac source, a 40-Ω resistor, a 0.70-H inductor, and a 60-μF
capacitor, as shown in the figure. The rms current in the circuit is 1.6 A. What is the voltage
amplitude of the source?
A) 390 V
B) 330 V
C) 270 V
D) 220 V
E) 190 V
90) A series circuit has a 100-Ω resistor, a 0.100–μF capacitor, and a 2.00-mH inductor
connected across a 120 V rms ac source operating at resonant frequency. What is the rms value
of the voltage across the inductor?
A) 170 V
B) 150 V
C) 120 V
D) 54.0 V
E) 533 V
91) A series circuit has a 100-Ω resistor, a 0.100–μF capacitor, and a 2.00-mH inductor
connected across a 120-V rms ac source operating at resonant frequency. What is the rms value
of the voltage across the capacitor?
A) 54.0 V
B) 120 V
C) 150 V
D) 533 V
E) 170 V
92) A series circuit has a 100-Ω resistor, a 0.100–μF capacitor, and a 2.00-mH inductor
connected across a 120-V rms ac source operating at 1000/π Hz. What is the rms voltage across
the inductor?
A) 120 mV
B) 87.1 mV
C) 302 mV
D) 96.1 mV
E) 200 mV
93) A series circuit consists of a 100-Ω resistor, a 10.0–μF capacitor, and a 0.350-H inductor.
The circuit is connected to a 120-V rms, 60-Hz power supply. What is the rms current in the
circuit?
A) 0.42 A
B) 0.52 A
C) 0.62 A
D) 0.72 A
94) A resistance of 55 Ω, a capacitor of capacitive reactance 30 Ω, and an inductor of inductive
reactance 30 Ω are connected in series to a 110-V rms, 60-Hz power source. What rms current
flows in this circuit?
A) 2.0 A
B) less than 2.0 A
C) more than 2.0 A
D) none of the given answers
95) A resistance of 55 Ω, a capacitor of capacitive reactance 30 Ω, and an inductor of inductive
reactance 30 Ω are connected in series to a 110-V rms 60-Hz power source. What rms current
flows in this circuit?
A) more than 4.0 A
B) 2.0 A
C) more than 2.0 A but less than 4.0 A
D) 4.0 A
E) less than 2.0 A
96) A series circuit consists of a 0.440-H inductor, a 380.0-Ω resistor, a 5.70-μF capacitor, and
an ac voltage source of amplitude Find the rms voltage across the capacitor when the
circuit operates at resonance.
97) A 120-mH inductor is in series with a 20-Ω resistor and a variable capacitor that can range
from 0.110 μF to 0.400 μF.
(a) What is the range of possible resonance frequencies?
(b) If the power supply is a 24-V rms source, what rms current flows at resonance?
98) What is the resonance frequency of a series ac circuit consisting of a 40.0 μF capacitor, a 55–
Ω resistor, and a 0.030 H inductor?
A) 0.15 kHz
B) 0.9 kHz
C) 6.9 kHz
D) 6 kHz
99) A series ac circuit has a resonance frequency of 9.0 kHz. If the inductor in the circuit has a
value of 2.0 H, and the resistance is 75 Ω, what is the capacitance of the circuit?
A) 0.16 pF
B) 156 pF
C) 6.2 pF
D) 17.7 pF
100) An ac circuit has a 100-Ω resistor in series with a 4.9–μF capacitor and a 700–mH inductor.
At what frequency does the circuit act like a pure resistance?
A) 0.29 MHz
B) 1.9 MHz
C) 12 MHz
D) 0.54 kHz
E) 86 Hz
101) A series RLC circuit has a 100-Ω resistor, a 0.100–μF capacitor and a 2.00-mH inductor
connected across a 120-V rms ac voltage source operating at 1000/π Hz. What is the resonant
frequency of this circuit?
A) 70.7 kHz
B) 17.9 kHz
C) 22.5 kHz
D) 35.3 kHz
E) 11.3 kHz
102) What size capacitor should be placed in series with a 30-Ω resistor and a 40-mH inductive
coil if the resonant frequency of the circuit is to be 1.0 kHz?
A) 2.0 µF
B) 0.63 µF
C) 3.3 µF
D) 6.0 µF
E) 4.5 µF