Question 1

An object that is giving off only infrared electromagnetic waves is giving off heat through:

Accepted Answer

A)  convection. 
B)  conduction. 
C)  radiation. 
D)  visible light. 
A)  convection. 
B)  conduction. 
C)  radiation. 
D)  visible light.

Question 2

A radar pulse sent out to an airplane at a distance of 24.1 km will return as an echo to the source in what time interval? (c = 3.00 × 108 m/s)

Accepted Answer

A)  33.3 × 10−6 s 
B)  80 × 10−6 s 
C)  161 × 10−6 s 
D)  40.2 × 10−6 s 
E)  ​482 × 10−6 s 
A)  33.3 × 10−6 s 
B)  80 × 10−6 s 
C)  161 × 10−6 s 
D)  40.2 × 10−6 s 
E)  ​482 × 10−6 s

Question 3

A series circuit has equal values for resistance,capacitive reactance,and inductive reactance.The phase angle for this circuit is:

Accepted Answer

A)  60°. 
B)  -60°. 
C)  180°. 
D)  not given. 
A)  60°. 
B)  -60°. 
C)  180°. 
D)  not given.

Question 4

In an AC series circuit,the current in a pure resistor differs in phase with the applied voltage by what angle?

Accepted Answer

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

Question 5

An electromagnetic wave with a peak magnetic field component of 1.06 × 10−7 T carries what average power per unit area? (μ0 = 4π × 10−7 T⋅m/A,ε0 = 8.85 × 10−12 C2/N⋅m2 and c = 3.00 × 108 m/s)

Accepted Answer

A)  4.21 W/m2 
B)  2.68 W/m2 
C)  1.34 W/m2 
D)  1.27 W/m2 
E)  ​2.53 W/m2 
A)  4.21 W/m2 
B)  2.68 W/m2 
C)  1.34 W/m2 
D)  1.27 W/m2 
E)  ​2.53 W/m2

Question 6

Consider an AC series circuit containing a coil,capacitor and resistance.Tripling the frequency will change the capacitive reactance by what factor?

Accepted Answer

A)  1/3.0 
B)  1.00 
C)  1.7 
D)  3.0 
E)  ​9.0 
A)  1/3.0 
B)  1.00 
C)  1.7 
D)  3.0 
E)  ​9.0

Question 7

What is the average power dissipation in an RLC series circuit in which R = 140 Ω,L = 0.38 H,and C = 10 µF driven at resonance by a 102-V (rms)source?

Accepted Answer

A)  70 W 
B)  9 W 
C)  15 W 
D)  26 W 
E)  ​92 W 
A)  70 W 
B)  9 W 
C)  15 W 
D)  26 W 
E)  ​92 W

Question 8

In an RLC series circuit the capacitive reactance is 43.6 Ω.If the AC frequency doubles,what will be the resulting capacitive reactance?

Accepted Answer

A)  30.8 Ω 
B)  21.8 Ω 
C)  61.7 Ω 
D)  87.2 Ω 
E)  ​Additional information is need to find the value. 
A)  30.8 Ω 
B)  21.8 Ω 
C)  61.7 Ω 
D)  87.2 Ω 
E)  ​Additional information is need to find the value.

Question 9

An observer is moving in space toward a distant star at 100 km/s while the star is moving toward the observer at 250 km/s;the relative velocity being 350 km/s of approach.What relative change in frequency of the light from the star as seen by the observer? (The speed of light in space is 3.00 × 105 km/s).

Accepted Answer

A)  0.12% increase 
B)  0.12% decrease 
C)  0.039% increase 
D)  0.35% decrease 
E)  ​0.35% increase 
A)  0.12% increase 
B)  0.12% decrease 
C)  0.039% increase 
D)  0.35% decrease 
E)  ​0.35% increase

Question 10

The human eye is sensitive to light with wavelength up to 380 nm.What is the frequency of radiation at this wavelength? (1 nm = 10−9 m and c = 3.00 × 108 m/s)

Accepted Answer

A)  7.89E+5 Hz 
B)  8.27E+6 Hz 
C)  7.89E+14 Hz 
D)  8.16E+7 Hz 
E)  ​4.08E+7 Hz 
A)  7.89E+5 Hz 
B)  8.27E+6 Hz 
C)  7.89E+14 Hz 
D)  8.16E+7 Hz 
E)  ​4.08E+7 Hz

Question 11

In order of increasing frequency,which of the following is correct?

Accepted Answer

A)  visible,radio,ultraviolet and x-ray 
B)  infrared,visible,ultraviolet and gamma 
C)  visible,gamma,ultraviolet and x-ray 
D)  infrared,x-ray,visible and gamma 
A)  visible,radio,ultraviolet and x-ray 
B)  infrared,visible,ultraviolet and gamma 
C)  visible,gamma,ultraviolet and x-ray 
D)  infrared,x-ray,visible and gamma

Question 12

Maxwell guessed that visible light was an electromagnetic wave because of its:

Accepted Answer

A)  frequency. 
B)  wavelength. 
C)  speed. 
D)  energy. 
A)  frequency. 
B)  wavelength. 
C)  speed. 
D)  energy.

Question 13

What value of inductance should be used in a series circuit with a capacitor of 1.4 × 10−3 μF when designed to radiate a wavelength of 24 m? (c = 3.00 × 108 m/s)

Accepted Answer

A)  7.3 mH 
B)  9.1 × 10−2 mH 
C)  2.3 × 10−3 mH 
D)  1.2 × 10−4 mH 
E)  ​46 mH 
A)  7.3 mH 
B)  9.1 × 10−2 mH 
C)  2.3 × 10−3 mH 
D)  1.2 × 10−4 mH 
E)  ​46 mH

Question 14

A transformer consists of a 705-turn primary coil and a 2757-turn secondary coil.If the current in the secondary is 1.11 A,what is the primary current?

Accepted Answer

A)  0.28 A 
B)  2.20 A 
C)  4.34 A 
D)  1.11 A 
E)  ​0.56 A 
A)  0.28 A 
B)  2.20 A 
C)  4.34 A 
D)  1.11 A 
E)  ​0.56 A

Question 15

In an RLC series circuit,if the AC frequency is increased to a very large value,what value does the phase angle between the current and voltage approach?

Accepted Answer

A)  90° 
B)  0° 
C)  -90° 
D)  45° 
A)  90° 
B)  0° 
C)  -90° 
D)  45°

Question 16

An FM radio tuning circuit has a coil with an inductance of 0.0021 mH.What is the value of the capacitance if the set is tuned to 102.7 MHz?

Accepted Answer

A)  4.6 × 10−6 μF 
B)  3.6 × 10−6 μF 
C)  7.4 × 10−6 μF 
D)  1.14 × 10−6 μF 
E)  ​11.3 × 10−6 μF 
A)  4.6 × 10−6 μF 
B)  3.6 × 10−6 μF 
C)  7.4 × 10−6 μF 
D)  1.14 × 10−6 μF 
E)  ​11.3 × 10−6 μF

Question 17

A 103-Ω resistor is connected in series with a 13.9-µF capacitor and a 88-Hz,225-V (rms)line voltage.If electrical energy costs 3.1¢ per kWh,how much does it cost to leave this circuit connected for 20 hours?

Accepted Answer

A)  5.0¢ 
B)  117.4¢ 
C)  1.22¢ 
D)  11.7¢ 
E)  ​12.2¢ 
A)  5.0¢ 
B)  117.4¢ 
C)  1.22¢ 
D)  11.7¢ 
E)  ​12.2¢

Question 18

An AM radio tuning circuit has a coil with an inductance of 1.65 mH and a capacitor set at 7.01 × 10−6 μF.What frequency will it detect?

Accepted Answer

A)  1236 kHz 
B)  1480 kHz 
C)  2470 kHz 
D)  236 kHz 
E)  ​740 kHz 
A)  1236 kHz 
B)  1480 kHz 
C)  2470 kHz 
D)  236 kHz 
E)  ​740 kHz

Exam 21: Alternating-Current Circuits and Electromagnetic Waves

An object that is giving off only infrared electromagnetic waves is giving off heat through:

A radar pulse sent out to an airplane at a distance of 24.1 km will return as an echo to the source in what time interval? (c = 3.00 × 108 m/s)

A series circuit has equal values for resistance,capacitive reactance,and inductive reactance.The phase angle for this circuit is:

In an AC series circuit,the current in a pure resistor differs in phase with the applied voltage by what angle?

An electromagnetic wave with a peak magnetic field component of 1.06 × 10−7 T carries what average power per unit area? (μ0 = 4π × 10−7 T⋅m/A,ε0 = 8.85 × 10−12 C2/N⋅m2 and c = 3.00 × 108 m/s)

Consider an AC series circuit containing a coil,capacitor and resistance.Tripling the frequency will change the capacitive reactance by what factor?

What is the average power dissipation in an RLC series circuit in which R = 140 Ω,L = 0.38 H,and C = 10 µF driven at resonance by a 102-V (rms)source?

In an RLC series circuit the capacitive reactance is 43.6 Ω.If the AC frequency doubles,what will be the resulting capacitive reactance?

The human eye is sensitive to light with wavelength up to 380 nm.What is the frequency of radiation at this wavelength? (1 nm = 10−9 m and c = 3.00 × 108 m/s)

In order of increasing frequency,which of the following is correct?

Maxwell guessed that visible light was an electromagnetic wave because of its:

What value of inductance should be used in a series circuit with a capacitor of 1.4 × 10−3 μF when designed to radiate a wavelength of 24 m? (c = 3.00 × 108 m/s)

A transformer consists of a 705-turn primary coil and a 2757-turn secondary coil.If the current in the secondary is 1.11 A,what is the primary current?

In an RLC series circuit,if the AC frequency is increased to a very large value,what value does the phase angle between the current and voltage approach?

An FM radio tuning circuit has a coil with an inductance of 0.0021 mH.What is the value of the capacitance if the set is tuned to 102.7 MHz?

A 103-Ω resistor is connected in series with a 13.9-µF capacitor and a 88-Hz,225-V (rms)line voltage.If electrical energy costs 3.1¢ per kWh,how much does it cost to leave this circuit connected for 20 hours?

An AM radio tuning circuit has a coil with an inductance of 1.65 mH and a capacitor set at 7.01 × 10−6 μF.What frequency will it detect?

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

Particle Collisions, Mediating Photons, and Quark Structures: Exploring the Fundamentals of Physics

Filters

A radar pulse sent out to an airplane at a distance of 24.1 km will return as an echo to the source in what time interval? (c = 3.00 × 10⁸ m/s)

An electromagnetic wave with a peak magnetic field component of 1.06 × 10−⁷ T carries what average power per unit area? (μ₀ = 4π × 10−⁷ T⋅m/A,ε₀ = 8.85 × 10−¹² C²/N⋅m² and c = 3.00 × 10⁸ m/s)

The human eye is sensitive to light with wavelength up to 380 nm.What is the frequency of radiation at this wavelength? (1 nm = 10−⁹ m and c = 3.00 × 10⁸ m/s)

What value of inductance should be used in a series circuit with a capacitor of 1.4 × 10−³ μF when designed to radiate a wavelength of 24 m? (c = 3.00 × 10⁸ m/s)

An AM radio tuning circuit has a coil with an inductance of 1.65 mH and a capacitor set at 7.01 × 10−⁶ μF.What frequency will it detect?