Question 1

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 2

A resistor and capacitor are connected in series with an applied AC voltage source.Separate voltmeter readings across the resistor and capacitor give values of 50 V and 75 V (rms),respectively.What is the effective (rms)voltage of the source?

Accepted Answer

A) 25 V 
B) 63 V 
C) 90 V 
D) 125 V 
A) 25 V 
B) 63 V 
C) 90 V 
D) 125 V

Question 3

What is the phase angle of an AC series circuit that is constructed of a 10.0-W resistor along with 12.00 W inductive reactance and 7.00 W capacitive reactance?

Accepted Answer

A) 26.6 $\degree$ 
B) 18.4 $\degree$ 
C) 87.0 $\degree$ 
D) 63.4 $\degree$ 
A) 26.6 $\degree$ 
B) 18.4 $\degree$ 
C) 87.0 $\degree$ 
D) 63.4 $\degree$

Question 4

An ideal transformer is one that:

Accepted Answer

A) has a turn ratio,N2/N1,equal to 1. 
B) works with direct current. 
C) experiences no power loss. 
D) has an output frequency of 60 Hz. 
A) has a turn ratio,N2/N1,equal to 1. 
B) works with direct current. 
C) experiences no power loss. 
D) has an output frequency of 60 Hz.

Question 5

A monochromatic light wave in vacuum has frequency f0 and wavelength l0.Which of the following are also possible frequency and wavelength combinations for a monochromatic light wave in vacuum?

Accepted Answer

A) 2f0,2l0 
B) f0/2,l0/2 
C) 2f0,l0/2 
D) None of the above are possible. 
A) 2f0,2l0 
B) f0/2,l0/2 
C) 2f0,l0/2 
D) None of the above are possible.

Question 6

The power factor in an AC series circuit is equal to which of the following ratios?

Accepted Answer

A) resistance to inductive reactance 
B) capacitive reactance to inductive reactance 
C) inductive reactance to capacitive reactance 
D) resistance to impedance 
A) resistance to inductive reactance 
B) capacitive reactance to inductive reactance 
C) inductive reactance to capacitive reactance 
D) resistance to impedance

Question 7

In an AC series circuit the capacitive reactance is 200 W and frequency is 100 Hz.What is the capacitance?

Accepted Answer

A) 3.2 mF 
B) 6.28 mF 
C) 8.0 mF 
D) 50.0 mF 
A) 3.2 mF 
B) 6.28 mF 
C) 8.0 mF 
D) 50.0 mF

Question 8

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

Accepted Answer

A) zero. 
B) equal to its resistance. 
C) a maximum. 
D) p/2 W. 
A) zero. 
B) equal to its resistance. 
C) a maximum. 
D) p/2 W.

Question 9

A solar cell has a light-gathering area of 10 cm2 and produces 0.20 A at 0.80 V (dc)when illuminated with sunlight of intensity 1 000 W/m2.What is the efficiency of the solar cell?

Accepted Answer

A) 16% 
B) 7% 
C) 23% 
D) 4% 
A) 16% 
B) 7% 
C) 23% 
D) 4%

Question 10

A transformer consists of a 500-turn primary coil and a 2 000-turn secondary coil.If the current in the secondary is 3.00 A,what is the primary current?

Accepted Answer

A) 0.750 A 
B) 1.33 A 
C) 12.0 A 
D) 48.0 A 
A) 0.750 A 
B) 1.33 A 
C) 12.0 A 
D) 48.0 A

Question 11

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

Accepted Answer

A) 60 $\degree$. 
B) -60 $\degree$. 
C) 180 $\degree$. 
D) not given. 
A) 60 $\degree$. 
B) -60 $\degree$. 
C) 180 $\degree$. 
D) not given.

Question 12

A 12.0-mF capacitor is connected to an AC source with an rms voltage of 120 V and a frequency of 60.0 Hz.What is the rms current in the capacitor?

Accepted Answer

A) 1.41 A 
B) 0.768 A 
C) 0.543 A 
D) 0 A 
A) 1.41 A 
B) 0.768 A 
C) 0.543 A 
D) 0 A

Question 13

The peak voltage of an AC source is 200 V.What is the rms voltage?

Accepted Answer

A) 282 V 
B) 200 V 
C) 141 V 
D) 100 V 
A) 282 V 
B) 200 V 
C) 141 V 
D) 100 V

Question 14

Glass panes are opaque to a certain type of radiation,which passes through quartz.What type of radiation is it? This radiation is important in ozone layer reactions.

Accepted Answer

A) microwave 
B) gamma 
C) x-ray 
D) ultraviolet 
A) microwave 
B) gamma 
C) x-ray 
D) ultraviolet

Question 15

In a space lab a 25-   sheet of aluminum foil having mass   is subjected to a laser beam of intensity   on one side and to a beam of intensity   on the opposite side,the radiation in each case hitting with normal incidence.If both of the aluminum foil sides are considered to be totally reflective and the foil is floating in the space lab,what acceleration of the foil will result from the net force from the incident beams?

Accepted Answer

A)    
B)    
C)    
D)    
A)    
B)    
C)    
D)

Question 16

A resistor,inductor and capacitor are connected in series,each with effective (rms)voltage of 65 V,140 V and 80 V,respectively.If the resistor is rated at 24 W,what is the average power dissipated in the circuit?

Accepted Answer

A) 88 W 
B) 176 W 
C) 238 W 
D) 323 W 
A) 88 W 
B) 176 W 
C) 238 W 
D) 323 W

Question 17

A series RLC AC circuit is at resonance.It contains a resistor of 30 W,a capacitor of 0.35 mF and an inductor of 90 mH.If an effective (rms)voltage of 150 V is applied,what is the effective (rms)current when the circuit is in resonance?

Accepted Answer

A) 3.3 A 
B) 5.0 A 
C) 9.4 A 
D) 16.1 A 
A) 3.3 A 
B) 5.0 A 
C) 9.4 A 
D) 16.1 A

Question 18

The power dissipated in an AC series circuit increases as the phase angle approaches what value?

Accepted Answer

A) zero 
B) 45 $\degree$ 
C) 90 $\degree$ 
D) 180 $\degree$ 
A) zero 
B) 45 $\degree$ 
C) 90 $\degree$ 
D) 180 $\degree$

Question 19

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 20

An electromagnetic wave with a peak magnetic field component of 1.5 x 10-7 T carries what average power per unit area? (m0 = 4p x 10-7 T*m/A,e0 = 8.85 x 10-12 C2/N*m2 and c = 3.00 x 108 m/s)

Accepted Answer

A) 12 W/m2 
B) 2.7 W/m2 
C) 3.0 W/m2 
D) 1.3 W/m2 
A) 12 W/m2 
B) 2.7 W/m2 
C) 3.0 W/m2 
D) 1.3 W/m2

Exam 21: Alternating Current Circuits and Electromagnetic Waves

The rms current is equal to the direct current that:

A resistor and capacitor are connected in series with an applied AC voltage source.Separate voltmeter readings across the resistor and capacitor give values of 50 V and 75 V (rms),respectively.What is the effective (rms)voltage of the source?

What is the phase angle of an AC series circuit that is constructed of a 10.0-W resistor along with 12.00 W inductive reactance and 7.00 W capacitive reactance?

An ideal transformer is one that:

A monochromatic light wave in vacuum has frequency f0 and wavelength l0.Which of the following are also possible frequency and wavelength combinations for a monochromatic light wave in vacuum?

The power factor in an AC series circuit is equal to which of the following ratios?

In an AC series circuit the capacitive reactance is 200 W and frequency is 100 Hz.What is the capacitance?

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

A solar cell has a light-gathering area of 10 cm2 and produces 0.20 A at 0.80 V (dc)when illuminated with sunlight of intensity 1 000 W/m2.What is the efficiency of the solar cell?

A transformer consists of a 500-turn primary coil and a 2 000-turn secondary coil.If the current in the secondary is 3.00 A,what is the primary current?

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

A 12.0-mF capacitor is connected to an AC source with an rms voltage of 120 V and a frequency of 60.0 Hz.What is the rms current in the capacitor?

The peak voltage of an AC source is 200 V.What is the rms voltage?

Glass panes are opaque to a certain type of radiation,which passes through quartz.What type of radiation is it? This radiation is important in ozone layer reactions.

A resistor,inductor and capacitor are connected in series,each with effective (rms)voltage of 65 V,140 V and 80 V,respectively.If the resistor is rated at 24 W,what is the average power dissipated in the circuit?

A series RLC AC circuit is at resonance.It contains a resistor of 30 W,a capacitor of 0.35 mF and an inductor of 90 mH.If an effective (rms)voltage of 150 V is applied,what is the effective (rms)current when the circuit is in resonance?

The power dissipated in an AC series circuit increases as the phase angle approaches what value?

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

An electromagnetic wave with a peak magnetic field component of 1.5 x 10-7 T carries what average power per unit area? (m0 = 4p x 10-7 T*m/A,e0 = 8.85 x 10-12 C2/N*m2 and c = 3.00 x 108 m/s)

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

A monochromatic light wave in vacuum has frequency f₀ and wavelength l₀.Which of the following are also possible frequency and wavelength combinations for a monochromatic light wave in vacuum?

A solar cell has a light-gathering area of 10 cm² and produces 0.20 A at 0.80 V (dc)when illuminated with sunlight of intensity 1 000 W/m².What is the efficiency of the solar cell?

An electromagnetic wave with a peak magnetic field component of 1.5 x 10^-7 T carries what average power per unit area? (m₀ = 4p x 10^-7Tm/A,e₀ = 8.85 x 10^-12 C²/Nm² and c = 3.00 x 10⁸ m/s)