Question 1

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

Question 2

A radio wave transmits 1.2 W/m2 average power per unit area.What is the peak value of the associated magnetic field? (m0 = 4p x 10-7 T*m/A and c = 3.00 x 108 m/s)

Accepted Answer

A) 1.0 x 10-7 T 
B) 8.4 x 10-3 T 
C) 1.2 T 
D) 30 T 
A) 1.0 x 10-7 T 
B) 8.4 x 10-3 T 
C) 1.2 T 
D) 30 T

Question 3

How is the direction of propagation of an electromagnetic wave oriented relative to the associated   and   fields?

Accepted Answer

A) parallel to both   and   
B) perpendicular to both   and   
C) parallel to   ,perpendicular to   
D) parallel to   ,perpendicular to   
A) parallel to both   and   
B) perpendicular to both   and   
C) parallel to   ,perpendicular to   
D) parallel to   ,perpendicular to

Question 4

What is the effective (rms)current value for an AC current with an amplitude of 10 A?

Accepted Answer

A) 28 A 
B) 3.1 A 
C) 7.1 A 
D) 14 A 
A) 28 A 
B) 3.1 A 
C) 7.1 A 
D) 14 A

Question 5

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 $\degree$ 
B) 0 $\degree$ 
C) -90 $\degree$ 
D) 45 $\degree$ 
A) 90 $\degree$ 
B) 0 $\degree$ 
C) -90 $\degree$ 
D) 45 $\degree$

Question 6

What is the maximum value of the electric field E at 1.0 m from a 100-W light bulb radiating in all directions? (µ0 = 4p x 10-7 T*m/A,c = 3.00 x 108 m/s)

Accepted Answer

A) 77 V/m 
B) 2 000 V/m 
C) 4 000 V/m 
D) 6 000 V/m 
A) 77 V/m 
B) 2 000 V/m 
C) 4 000 V/m 
D) 6 000 V/m

Question 7

A resistor,inductor,and capacitor are connected in series,each with effective (rms)voltage of 65 V,140 V,and 80 V,respectively.What is the value of the effective (rms)voltage of the applied source in the circuit?

Accepted Answer

A) 48 V 
B) 88 V 
C) 95 V 
D) 285 V 
A) 48 V 
B) 88 V 
C) 95 V 
D) 285 V

Question 8

In the typical household AC voltage of 120 V,what is the peak voltage?

Accepted Answer

A) 240 V 
B) 170 V 
C) 120 V 
D) 85 V 
A) 240 V 
B) 170 V 
C) 120 V 
D) 85 V

Question 9

In the inductor of a 60-Hz AC series circuit,the peak voltage precedes the peak current in each cycle by what time interval?

Accepted Answer

A) 2.1 x 10-3 s 
B) 4.2 x 10-3 s 
C) 8.3 x 10-3 s 
D) 1.7 x 10-3 s 
A) 2.1 x 10-3 s 
B) 4.2 x 10-3 s 
C) 8.3 x 10-3 s 
D) 1.7 x 10-3 s

Question 10

An FM radio tuning circuit has a coil with an inductance of 0.003 0 mH.What is the value of the capacitance if the set is tuned to 98 MHz?

Accepted Answer

A) 1.8 x 10-6 mF 
B) 12 x 10-6 mF 
C) 0.98 x 10-6 mF 
D) 0.88 x 10-6 mF 
A) 1.8 x 10-6 mF 
B) 12 x 10-6 mF 
C) 0.98 x 10-6 mF 
D) 0.88 x 10-6 mF

Question 11

Peak values for a neodymium-glass laser are 600 J for 1 nanosecond.If the cross-section of the laser beam is 1 cm2,what are the maximum values of E and B? (µ0 = 4p x 10-7 T*m/A,c = 3.00 x 108 m/s)

Accepted Answer

A) 2 x 109 V/m,2 T 
B) 4 x 108 V/m,7 T 
C) 2 x 109 V/m,7 T 
D) 4 x 108 V/m,2 T 
A) 2 x 109 V/m,2 T 
B) 4 x 108 V/m,7 T 
C) 2 x 109 V/m,7 T 
D) 4 x 108 V/m,2 T

Question 12

A series RLC circuit in a radio is in resonance with AM 600 kHz.If the radio station is changed to AM 1 200 kHz,by what factor must the capacitance be multiplied to again achieve resonance?

Accepted Answer

A) 4 
B) 2 
C) 1/2 
D) 1/4 
A) 4 
B) 2 
C) 1/2 
D) 1/4

Question 13

Microwave radiation is useful in which of the following?

Accepted Answer

A) sending phone messages 
B) cooking food 
C) aircraft navigation 
D) All of the above are valid choices. 
A) sending phone messages 
B) cooking food 
C) aircraft navigation 
D) All of the above are valid choices.

Question 14

An ultraviolet light wave has a wavelength of 300 nm and speed of 2.1 x 108 m/s through a transparent medium.What is the frequency of this wave in the medium? (1 nm = 10-9 m and c = 3.00 x 108 m/s)

Accepted Answer

A) 6.3 x 102 Hz 
B) 9.0 x 102 Hz 
C) 7.0 x 1014 Hz 
D) 10 x 1014 Hz 
A) 6.3 x 102 Hz 
B) 9.0 x 102 Hz 
C) 7.0 x 1014 Hz 
D) 10 x 1014 Hz

Question 15

An AC series circuit contains a resistor of 20 W,a capacitor of 0.75 mF and an inductor of 120 mH.What frequency should be used to create a resonance condition in the circuit?

Accepted Answer

A) 160 Hz 
B) 320 Hz 
C) 640 Hz 
D) 530 Hz 
A) 160 Hz 
B) 320 Hz 
C) 640 Hz 
D) 530 Hz

Question 16

An electromagnetic wave with a peak electric field component of 1.2 x 102 N/C has what associated peak magnetic field value? (e0 = 8.85 x 10-12 C2/N*m2, m0 = 4p x 10-7 T*m/A and c = 3.00 x 108 m/s)

Accepted Answer

A) 4.0 x 10-7 T 
B) 3.6 x 1010 T 
C) 2.5 x 106 T 
D) 2.8 x 10-11 T 
A) 4.0 x 10-7 T 
B) 3.6 x 1010 T 
C) 2.5 x 106 T 
D) 2.8 x 10-11 T

Question 17

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 18

What is the average power dissipation in a series RC circuit if R = 5.00 kW,C = 2.00 µF,and V = (170 V)cos 300t?

Accepted Answer

A) 2.60 W 
B) 2.74 W 
C) 28.2 W 
D) 157 W 
A) 2.60 W 
B) 2.74 W 
C) 28.2 W 
D) 157 W

Question 19

A transformer is to be designed to increase the 30-kV (rms)output of a generator to the transmission line voltage of 345 kV (rms).If the primary winding has 80 turns,how many turns must the secondary have?

Accepted Answer

A) 6 
B) 70 
C) 920 
D) 9 200 
A) 6 
B) 70 
C) 920 
D) 9 200

Question 20

Which one of the following scientists made the theoretical prediction that electromagnetic waves travel through a vacuum at the speed of light?

Accepted Answer

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

Exam 21: Alternating Current Circuits and Electromagnetic Waves

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

A radio wave transmits 1.2 W/m2 average power per unit area.What is the peak value of the associated magnetic field? (m0 = 4p x 10-7 T*m/A and c = 3.00 x 108 m/s)

How is the direction of propagation of an electromagnetic wave oriented relative to the associated and fields?

What is the effective (rms)current value for an AC current with an amplitude of 10 A?

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?

What is the maximum value of the electric field E at 1.0 m from a 100-W light bulb radiating in all directions? (µ0 = 4p x 10-7 T*m/A,c = 3.00 x 108 m/s)

A resistor,inductor,and capacitor are connected in series,each with effective (rms)voltage of 65 V,140 V,and 80 V,respectively.What is the value of the effective (rms)voltage of the applied source in the circuit?

In the typical household AC voltage of 120 V,what is the peak voltage?

In the inductor of a 60-Hz AC series circuit,the peak voltage precedes the peak current in each cycle by what time interval?

An FM radio tuning circuit has a coil with an inductance of 0.003 0 mH.What is the value of the capacitance if the set is tuned to 98 MHz?

Peak values for a neodymium-glass laser are 600 J for 1 nanosecond.If the cross-section of the laser beam is 1 cm2,what are the maximum values of E and B? (µ0 = 4p x 10-7 T*m/A,c = 3.00 x 108 m/s)

A series RLC circuit in a radio is in resonance with AM 600 kHz.If the radio station is changed to AM 1 200 kHz,by what factor must the capacitance be multiplied to again achieve resonance?

Microwave radiation is useful in which of the following?

An ultraviolet light wave has a wavelength of 300 nm and speed of 2.1 x 108 m/s through a transparent medium.What is the frequency of this wave in the medium? (1 nm = 10-9 m and c = 3.00 x 108 m/s)

An AC series circuit contains a resistor of 20 W,a capacitor of 0.75 mF and an inductor of 120 mH.What frequency should be used to create a resonance condition in the circuit?

An electromagnetic wave with a peak electric field component of 1.2 x 102 N/C has what associated peak magnetic field value? (e0 = 8.85 x 10-12 C2/N*m2, m0 = 4p x 10-7 T*m/A and c = 3.00 x 108 m/s)

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

What is the average power dissipation in a series RC circuit if R = 5.00 kW,C = 2.00 µF,and V = (170 V)cos 300t?

A transformer is to be designed to increase the 30-kV (rms)output of a generator to the transmission line voltage of 345 kV (rms).If the primary winding has 80 turns,how many turns must the secondary have?

Which one of the following scientists made the theoretical prediction that electromagnetic waves travel through a vacuum at the speed of light?

Introduction

Motion in One Dimension

Vectors and Two-Dimensional Motion

The Laws of Motion

Energy

Momentum and Collisions

Rotational Motion and the Law of Gravity

Rotational Equilibrium and Rotational Dynamics

Solids and Fluids

Thermal Physics

Energy in Thermal Processes

The Laws of Thermodynamics

Vibrations and Waves

Sound

Electric Forces and Electric Fields

Electrical Energy and Capacitance

Current and Resistance

Direct-Current Circuits

Magnetism

Induced Voltages and Inductance

Reflection and Refraction of Light

Mirrors and Lenses

Wave Optics

Optical Instruments

Relativity

Quantum Physics

Atomic Physics

Nuclear Physics

Nuclear Energy and Elementary Particles

Filters

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 radio wave transmits 1.2 W/m² average power per unit area.What is the peak value of the associated magnetic field? (m₀ = 4p x 10^-7 T*m/A and c = 3.00 x 10⁸ m/s)

What is the maximum value of the electric field E at 1.0 m from a 100-W light bulb radiating in all directions? (µ₀ = 4p x 10^-7 T*m/A,c = 3.00 x 10⁸ m/s)

Peak values for a neodymium-glass laser are 600 J for 1 nanosecond.If the cross-section of the laser beam is 1 cm²,what are the maximum values of E and B? (µ₀ = 4p x 10^-7 T*m/A,c = 3.00 x 10⁸ m/s)

An ultraviolet light wave has a wavelength of 300 nm and speed of 2.1 x 10⁸m/s through a transparent medium.What is the frequency of this wave in the medium? (1 nm = 10^-9 m and c = 3.00 x 10⁸ m/s)

An electromagnetic wave with a peak electric field component of 1.2 x 10² N/C has what associated peak magnetic field value? (e₀ = 8.85 x 10^-12 C²/Nm²,m₀ = 4p x 10^-7 Tm/A and c = 3.00 x 10⁸ m/s)