Question 1

A 120-V rms voltage at 90 Hz is applied across a 20-μF capacitor and a 100-Ω resistor. What is the rms value of the current in that circuit?

Accepted Answer

A)  0.6 A 
B)  0.7 A 
C)  0.8 A 
D)  0.9 A 
E)  1.0 A 
A)  0.6 A 
B)  0.7 A 
C)  0.8 A 
D)  0.9 A 
E)  1.0 A

Question 2

A certain ac signal at 60 Hz is applied across a 40-mH inductor and a 200-Ω resistor. What is the power factor of this circuit?

Accepted Answer

A)  0.249 
B)  0.497 
C)  0.697 
D)  0.997 
E)  None of the other answers is correct. 
A)  0.249 
B)  0.497 
C)  0.697 
D)  0.997 
E)  None of the other answers is correct.

Question 3

A 60.0-μF capacitor is in series with a 100-Ω resistor connected across an ac source of frequency 120 Hz. What is the phase angle?

Accepted Answer

A)  -12.4° 
B)  +12.4° 
C)  -77.6° 
D)  +77.6° 
E)  90.0° 
A)  -12.4° 
B)  +12.4° 
C)  -77.6° 
D)  +77.6° 
E)  90.0°

Question 4

The phase angle of an RLC series circuit with an inductive reactance of 200 Ω, a resistor of 200 Ω and a certain capacitor at 1000 Hz is 40.0°. What is the value of the capacitance in this circuit?

Accepted Answer

A)  1.95 μF 
B)  2.95 μF 
C)  3.95 μF 
D)  4.95 μF 
E)  5.95 μF 
A)  1.95 μF 
B)  2.95 μF 
C)  3.95 μF 
D)  4.95 μF 
E)  5.95 μF

Question 5

A 120-V rms voltage at 1000 Hz is applied to a 2.00-mH inductor, a 4.00-μF capacitor and a resistor. If the rms value of the current in this circuit is 0.400 A, what is the value of the resistor?

Accepted Answer

A)  299 Ω 
B)  95.1 Ω 
C)  423 Ω 
D)  120 Ω 
E)  240 Ω 
A)  299 Ω 
B)  95.1 Ω 
C)  423 Ω 
D)  120 Ω 
E)  240 Ω

Question 6

A 120-V rms voltage at 60.0 Hz is applied across an inductor, capacitor and a 100-Ω resistor in series. If the maximum value of the current in this circuit is 1.60 A, what is the rms value of the current in this circuit?

Accepted Answer

A)  1.13 A 
B)  2.26 A 
C)  1.82 A 
D)  1.60 A 
E)  2.66 A 
A)  1.13 A 
B)  2.26 A 
C)  1.82 A 
D)  1.60 A 
E)  2.66 A

Question 7

The phase angle of a series RL circuit with a 20.0-mH inductor and a certain resistor at 1000 Hz is 20.0°. What is the value of the resistance in this circuit?

Accepted Answer

A)  145 Ω 
B)  100 Ω 
C)  245 Ω 
D)  200 Ω 
E)  345 Ω 
A)  145 Ω 
B)  100 Ω 
C)  245 Ω 
D)  200 Ω 
E)  345 Ω

Question 8

What is the power factor of an RLC series circuit with an inductive reactance of 174 Ω, a capacitive reactance of 60 Ω and a resistance of 100 Ω?

Accepted Answer

A)  0.29 
B)  0.46 
C)  0.56 
D)  0.66 
E)  0.76 
A)  0.29 
B)  0.46 
C)  0.56 
D)  0.66 
E)  0.76

Question 9

A 100-Ω resistor is connected in series with a 10-mH inductor across an ac source operating at 1000 Hz. What is the impedance of this circuit?

Accepted Answer

A)  100 Ω 
B)  118 Ω 
C)  200 Ω 
D)  236 Ω 
E)  1000 Ω 
A)  100 Ω 
B)  118 Ω 
C)  200 Ω 
D)  236 Ω 
E)  1000 Ω

Question 10

A 200-Ω resistor, a 25-mH inductor, and a capacitor are connected in series across an ac voltage source at 1000 Hz. If the impedance of this circuit is 240 Ω, what is the value of the capacitor?

Accepted Answer

A)  5.5 μF 
B)  3.2 μF 
C)  4.2 μF 
D)  6.5 μF 
E)  7.5 μF 
A)  5.5 μF 
B)  3.2 μF 
C)  4.2 μF 
D)  6.5 μF 
E)  7.5 μF

Question 11

What is the inductive reactance of a 20-mH inductor at a frequency of 60 Hz?

Accepted Answer

A)  7.5 Ω 
B)  0.13 Ω 
C)  1.2 Ω 
D)  1.2 mΩ 
E)  7.5 mΩ 
A)  7.5 Ω 
B)  0.13 Ω 
C)  1.2 Ω 
D)  1.2 mΩ 
E)  7.5 mΩ

Question 12

A 120-V rms voltage at 60.0 Hz is applied across an inductor, a capacitor, and a resistor in series. If the rms value of the current in this circuit is 0.600 A, what is the impedance of this circuit?

Accepted Answer

A)  200 Ω 
B)  141 Ω 
C)  20 4 Ω 
D)  120 Ω 
E)  100 Ω 
A)  200 Ω 
B)  141 Ω 
C)  20 4 Ω 
D)  120 Ω 
E)  100 Ω

Question 13

Consider an RLC series circuit. The impedance of the circuit increases if XC increases.

Accepted Answer

A)  true only if XL is greater than or equal to XC 
B)  true only if XL is less than or equal to XC 
C)  always true 
D)  never true 
A)  true only if XL is greater than or equal to XC 
B)  true only if XL is less than or equal to XC 
C)  always true 
D)  never true

Exam 24: Alternating-Current Circuits

A 120-V rms voltage at 90 Hz is applied across a 20-μF capacitor and a 100-Ω resistor. What is the rms value of the current in that circuit?

A certain ac signal at 60 Hz is applied across a 40-mH inductor and a 200-Ω resistor. What is the power factor of this circuit?

A 60.0-μF capacitor is in series with a 100-Ω resistor connected across an ac source of frequency 120 Hz. What is the phase angle?

The phase angle of an RLC series circuit with an inductive reactance of 200 Ω, a resistor of 200 Ω and a certain capacitor at 1000 Hz is 40.0°. What is the value of the capacitance in this circuit?

A 120-V rms voltage at 1000 Hz is applied to a 2.00-mH inductor, a 4.00-μF capacitor and a resistor. If the rms value of the current in this circuit is 0.400 A, what is the value of the resistor?

A 120-V rms voltage at 60.0 Hz is applied across an inductor, capacitor and a 100-Ω resistor in series. If the maximum value of the current in this circuit is 1.60 A, what is the rms value of the current in this circuit?

The phase angle of a series RL circuit with a 20.0-mH inductor and a certain resistor at 1000 Hz is 20.0°. What is the value of the resistance in this circuit?

What is the power factor of an RLC series circuit with an inductive reactance of 174 Ω, a capacitive reactance of 60 Ω and a resistance of 100 Ω?

A 100-Ω resistor is connected in series with a 10-mH inductor across an ac source operating at 1000 Hz. What is the impedance of this circuit?

A 200-Ω resistor, a 25-mH inductor, and a capacitor are connected in series across an ac voltage source at 1000 Hz. If the impedance of this circuit is 240 Ω, what is the value of the capacitor?

What is the inductive reactance of a 20-mH inductor at a frequency of 60 Hz?

A 120-V rms voltage at 60.0 Hz is applied across an inductor, a capacitor, and a resistor in series. If the rms value of the current in this circuit is 0.600 A, what is the impedance of this circuit?

Consider an RLC series circuit. The impedance of the circuit increases if XC increases.

Introduction to Physics

One-Dimensional Kinematics

Vectors in Physics

Two-Dimensional Kinematics

Newtons Laws of Motion

Applications of Newtons Laws

Work and Kinetic Energy

Potential Energy and Conservation of Energy

Linear Momentum and Collisions

Rotational Kinematics and Energy

Rotational Dynamics and Static Equilibrium

Gravity

Oscillations About Equilibrium

Waves and Sound

Fluids

Temperature and Heat

Phases and Phase Changes

The Laws of Thermodynamics

Electric Charges, Forces, and Fields

Electric Potential and Electric Potential Energy

Electric Current and Direct-Current Circuits

Magnetism

Magnetic Flux and Faradays Law of Induction

Electromagnetic Waves

Geometrical Optics

Optical Instruments

Physical Optics: Interference and Diffraction

Relativity

Quantum Physics

Atomic Physics

Nuclear Physics and Nuclear Radiation

Filters

Consider an RLC series circuit. The impedance of the circuit increases if X_C increases.