Question 1

The frequency in an AC series circuit is tripled.By what factor does this change the capacitive reactance?

Accepted Answer

A)  1/3 
B)  1/9 
C)  3 
D)  9 
E)  ​1 
A)  1/3 
B)  1/9 
C)  3 
D)  9 
E)  ​1

Question 2

In an AC series circuit,the voltage in the inductor differs in phase with the voltage in the capacitor by what angle?

Accepted Answer

A)  zero 
B)  45° 
C)  90° 
D)  180° 
A)  zero 
B)  45° 
C)  90° 
D)  180°

Question 3

An electromagnetic wave is made up of which of the following oscillating quantities?

Accepted Answer

A)  electrons only 
B)  electric fields only 
C)  magnetic fields only 
D)  electric and magnetic fields 
A)  electrons only 
B)  electric fields only 
C)  magnetic fields only 
D)  electric and magnetic fields

Question 4

In a 60-Hz RLC circuit,the phase angle is positive.The values of the resistance,inductance,and the capacitance are now doubled.Which of the following is now true about the phase angle?

Accepted Answer

A)  It is still positive. 
B)  It could be zero. 
C)  It will be negative. 
D)  It could be positive,negative,or zero,but it cannot be greater than its original value. 
A)  It is still positive. 
B)  It could be zero. 
C)  It will be negative. 
D)  It could be positive,negative,or zero,but it cannot be greater than its original value.

Question 5

As an electromagnetic wave travels through free space,its speed can be increased by:

Accepted Answer

A)  increasing its frequency. 
B)  increasing its energy only. 
C)  increasing both its energy and momentum. 
D)  None of the above will increase its speed. 
A)  increasing its frequency. 
B)  increasing its energy only. 
C)  increasing both its energy and momentum. 
D)  None of the above will increase its speed.

Question 6

The rms current is equal to the direct current that:

Accepted Answer

A)  produces the same average voltage across a resistor as in an AC circuit. 
B)  dissipates an equal amount of energy in a resistor at the same rate as in an AC circuit. 
C)  provides the same average current in a resistor as in an AC circuit. 
D)  results in the same peak power in a resistor as in an AC circuit. 
A)  produces the same average voltage across a resistor as in an AC circuit. 
B)  dissipates an equal amount of energy in a resistor at the same rate as in an AC circuit. 
C)  provides the same average current in a resistor as in an AC circuit. 
D)  results in the same peak power in a resistor as in an AC circuit.

Question 7

What is the average power dissipation in a series RC circuit if R = 2.12 kΩ,C = 2.25 µF,and V = (267 V)cos 479t?

Accepted Answer

A)  14.1 W 
B)  33.6 W 
C)  16.8 W 
D)  20.0 W 
E)  ​39.9 W 
A)  14.1 W 
B)  33.6 W 
C)  16.8 W 
D)  20.0 W 
E)  ​39.9 W

Question 8

An AC power generator produces 60.64 A (rms)at 2195 V.The voltage is stepped up to 104,222 V by an ideal transformer,and the energy transmitted through a long-distance power line with a total resistance of 100 Ω.What is the rms current in the long-distance line?

Accepted Answer

A)  2879 A 
B)  1.28 A 
C)  60.64 A 
D)  8.80 A 
E)  ​417.9 A 
A)  2879 A 
B)  1.28 A 
C)  60.64 A 
D)  8.80 A 
E)  ​417.9 A

Question 9

The rate of heat dissipation in an AC circuit with resistance,R,and effective current,Irms,is given by which of the following?

Accepted Answer

A)  0.5 × (Irms)2R 
B)  (Irms)2R 
C)  2.0 × (Irms)2R 
D)  4.0 × (Irms)2R 
A)  0.5 × (Irms)2R 
B)  (Irms)2R 
C)  2.0 × (Irms)2R 
D)  4.0 × (Irms)2R

Question 10

In an RC circuit,which of the following is a possible phase angle?

Accepted Answer

A)  45° 
B)  -45° 
C)  135° 
D)  -135° 
A)  45° 
B)  -45° 
C)  135° 
D)  -135°

Question 11

A monochromatic light wave in vacuum has frequency f0 and wavelength λ0.Which of the following are also possible frequency and wavelength combinations for a monochromatic light wave in vacuum?

Accepted Answer

A)  2f0,2λ0 
B)  f0/2,λ0/2 
C)  2f0,λ0/2 
D)  None of the above are possible. 
A)  2f0,2λ0 
B)  f0/2,λ0/2 
C)  2f0,λ0/2 
D)  None of the above are possible.

Question 12

In the typical household AC voltage of 119 V,what is the peak voltage?

Accepted Answer

A)  238 V 
B)  168 V 
C)  119 V 
D)  84 V 
E)  ​60 V 
A)  238 V 
B)  168 V 
C)  119 V 
D)  84 V 
E)  ​60 V

Question 13

A 48-Ω resistor,a 0.42-H inductor,and a 9.7-µF capacitor are connected in series to a 40-Hz source.The rms current in the circuit is 3.43 A.Find the rms voltage across the resistor,the inductor,and the capacitor.

Accepted Answer

A)  165 V,362 V,1407 V (all rms) 
B)  165 V,362 V,236 V (all rms) 
C)  1407V,58V,236V (all rms) 
D)  517 V,58 V,1407 V (all rms) 
E)  ​517 V,362 V,236 V (all rms) 
A)  165 V,362 V,1407 V (all rms) 
B)  165 V,362 V,236 V (all rms) 
C)  1407V,58V,236V (all rms) 
D)  517 V,58 V,1407 V (all rms) 
E)  ​517 V,362 V,236 V (all rms)

Question 14

When an RLC series circuit is in resonance,its impedance is:

Accepted Answer

A)  zero. 
B)  equal to its resistance. 
C)  a maximum. 
D)  π/2 Ω. 
A)  zero. 
B)  equal to its resistance. 
C)  a maximum. 
D)  π/2 Ω.

Question 15

Which one of the following scientists first built and operated devices that could emit and detect man-made electromagnetic radiation?

Accepted Answer

A)  Hertz 
B)  Ampere 
C)  Maxwell 
D)  Lenz 
A)  Hertz 
B)  Ampere 
C)  Maxwell 
D)  Lenz

Question 16

An electromagnetic wave with a peak electric field component of 1.74 × 102 N/C has what associated peak magnetic field value? (ε0 = 8.85 × 10−12 C2/N⋅m2,μ0 = 4π × 10−7 T⋅m/A and c = 3.00 × 108 m/s)

Accepted Answer

A)  5.22E+10 T 
B)  1.72E+6 T 
C)  5.80E-7 T 
D)  7.29E-13 T 
E)  ​1.15E+4 T 
A)  5.22E+10 T 
B)  1.72E+6 T 
C)  5.80E-7 T 
D)  7.29E-13 T 
E)  ​1.15E+4 T

Question 17

What is the effective (rms)current value for an AC current with an amplitude of 14 A?

Accepted Answer

A)  14 A 
B)  7.0 A 
C)  9.9 A 
D)  3.7 A 
E)  ​2.6 A 
A)  14 A 
B)  7.0 A 
C)  9.9 A 
D)  3.7 A 
E)  ​2.6 A

Question 18

In an AC series circuit the inductive reactance is 43.0 Ω and the frequency is 160 Hz.What is the inductance in the circuit?

Accepted Answer

A)  42.8 mH 
B)  134 mH 
C)  269 mH 
D)  422 mH 
E)  ​207 mH 
A)  42.8 mH 
B)  134 mH 
C)  269 mH 
D)  422 mH 
E)  ​207 mH

Question 19

An AC series circuit has 10.02-Ω resistance,19.78-Ω inductive reactance,and 7.40-Ω capacitive reactance.If an effective (rms)emf of 111 V is applied,what is the power output?

Accepted Answer

A)  620 W 
B)  230 W 
C)  1210 W 
D)  490 W 
E)  ​590 W 
A)  620 W 
B)  230 W 
C)  1210 W 
D)  490 W 
E)  ​590 W

Question 20

An AC power generator produces 14 A (rms)at 2103 V.The energy is transmitted through a long-distance power line,which has a total resistance of 145 Ω.What percentage of the power delivered by the generator is dissipated as heat in the long-distance line if a step-up transformer is not used?

Accepted Answer

A)  3% 
B)  19% 
C)  31% 
D)  97% 
E)  ​93% 
A)  3% 
B)  19% 
C)  31% 
D)  97% 
E)  ​93%

Exam 21: Alternating-Current Circuits and Electromagnetic Waves

The frequency in an AC series circuit is tripled.By what factor does this change the capacitive reactance?

In an AC series circuit,the voltage in the inductor differs in phase with the voltage in the capacitor by what angle?

An electromagnetic wave is made up of which of the following oscillating quantities?

In a 60-Hz RLC circuit,the phase angle is positive.The values of the resistance,inductance,and the capacitance are now doubled.Which of the following is now true about the phase angle?

As an electromagnetic wave travels through free space,its speed can be increased by:

The rms current is equal to the direct current that:

What is the average power dissipation in a series RC circuit if R = 2.12 kΩ,C = 2.25 µF,and V = (267 V)cos 479t?

An AC power generator produces 60.64 A (rms)at 2195 V.The voltage is stepped up to 104,222 V by an ideal transformer,and the energy transmitted through a long-distance power line with a total resistance of 100 Ω.What is the rms current in the long-distance line?

The rate of heat dissipation in an AC circuit with resistance,R,and effective current,Irms,is given by which of the following?

In an RC circuit,which of the following is a possible phase angle?

A monochromatic light wave in vacuum has frequency f0 and wavelength λ0.Which of the following are also possible frequency and wavelength combinations for a monochromatic light wave in vacuum?

In the typical household AC voltage of 119 V,what is the peak voltage?

A 48-Ω resistor,a 0.42-H inductor,and a 9.7-µF capacitor are connected in series to a 40-Hz source.The rms current in the circuit is 3.43 A.Find the rms voltage across the resistor,the inductor,and the capacitor.

When an RLC series circuit is in resonance,its impedance is:

Which one of the following scientists first built and operated devices that could emit and detect man-made electromagnetic radiation?

An electromagnetic wave with a peak electric field component of 1.74 × 102 N/C has what associated peak magnetic field value? (ε0 = 8.85 × 10−12 C2/N⋅m2,μ0 = 4π × 10−7 T⋅m/A and c = 3.00 × 108 m/s)

What is the effective (rms)current value for an AC current with an amplitude of 14 A?

In an AC series circuit the inductive reactance is 43.0 Ω and the frequency is 160 Hz.What is the inductance in the circuit?

An AC series circuit has 10.02-Ω resistance,19.78-Ω inductive reactance,and 7.40-Ω capacitive reactance.If an effective (rms)emf of 111 V is applied,what is the power output?

An AC power generator produces 14 A (rms)at 2103 V.The energy is transmitted through a long-distance power line,which has a total resistance of 145 Ω.What percentage of the power delivered by the generator is dissipated as heat in the long-distance line if a step-up transformer is not used?

Introduction

Introduction: Part A

Motion in One Dimension

Motion in One Dimension: Part A

Vectors and Two-Dimensional Motion

Vectors and Two-Dimensional Motion: Part A

The Laws of Motion

The Laws of Motion: Part A

Energy

Energy: Part A

Momentum and Collisions

Momentum and Collisions: Part A

Rotational Motion and the Law of Gravity

Rotational Motion and the Law of Gravity: Part A

Rotational Equilibrium and Rotational Dynamics

Rotational Equilibrium and Rotational Dynamics: Part A

Solids and Fluids

Solids and Fluids: Part A

Thermal Physics

Thermal Physics: Part A

Energy in Thermal Processes Heat and Internal Energy

Energy in Thermal Processes Heat and Internal Energy: Part A

The Laws of Thermodynamics Work in Thermodynamic Processes

The Laws of Thermodynamics Work in Thermodynamic Processes: Part A

Vibrations and Waves

Vibrations and Waves: Part A

Sound

Sound: Part A

Electric Forces and Electric Fields

Electric Forces and Electric Fields: Part A

Electrical Energy and Capacitance

Electrical Energy and Capacitance: Part A

Current and Resistance Electric Current

Current and Resistance Electric Current: Part A

Direct-Current Circuits Sources of EMF

Direct-Current Circuits Sources of EMF: Part A

Magnetism Magnets

Magnetism Magnets: Part A

Induced Voltages and Inductance

Induced Voltages and Inductance: Part A

Alternating-Current Circuits and Electromagnetic Waves: Part A

Reflection and Refraction of Light

Reflection and Refraction of Light: Part A

Mirrors and Lenses

Mirrors and Lenses: Part A

Wave Optics

Wave Optics: Part A

Optical Instruments

Optical Instruments: Part A

Relativity

Relativity: Part A

Quantum Physics Blackbody Radiation and Plancks Hypothesis

Quantum Physics Blackbody Radiation and Plancks Hypothesis: Part A

Atomic Physics

Atomic Physics: Part A

Nuclear Physics

Nuclear Physics: Part A

Nuclear Energy and Elementary Particles

Nuclear Energy and Elementary Particles: Part A

The rate of heat dissipation in an AC circuit with resistance,R,and effective current,I_rms,is given by which of the following?

A monochromatic light wave in vacuum has frequency f₀ and wavelength λ₀.Which of the following are also possible frequency and wavelength combinations for a monochromatic light wave in vacuum?

An electromagnetic wave with a peak electric field component of 1.74 × 10² N/C has what associated peak magnetic field value? (ε₀ = 8.85 × 10−¹² C²/N⋅m²,μ₀ = 4π × 10−⁷ T⋅m/A and c = 3.00 × 10⁸ m/s)