Question 1

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

Accepted Answer

A) 45$\degree$ 
B) -45$\degree$ 
C) 135$\degree$ 
D) -135$\degree$ 
A) 45$\degree$ 
B) -45$\degree$ 
C) 135$\degree$ 
D) -135$\degree$ C

Question 2

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 D

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
  C

Question 4

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 5

An AC voltage source, with a peak output of 200 V, is connected to a 50-W resistor.What is the rate of energy dissipated due to heat in the resistor?

Accepted Answer

A) 200 W 
B) 400 W 
C) 566 W 
D) 800 W 
A) 200 W 
B) 400 W 
C) 566 W 
D) 800 W

Question 6

In an RLC series circuit the capacitive reactance is 24 W.If the AC frequency doubles, what will be the resulting capacitive reactance?

Accepted Answer

A) 24 W 
B) 12 W 
C) 48 W 
D) Additional information is need to find the value. 
A) 24 W 
B) 12 W 
C) 48 W 
D) Additional information is need to find the value.

Question 7

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 8

An observer is moving in space toward a distant star at 100 km/s while the star is moving toward the observer at 200 km/s; the relative velocity being 300 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) 0.10% increase 
B) 0.10% decrease 
C) 0.067% increase 
D) 0.033% decrease 
A) 0.10% increase 
B) 0.10% decrease 
C) 0.067% increase 
D) 0.033% decrease

Question 9

Maxwell developed his theory of electromagnetism by combining previous discoveries.He added his own original hypothesis that:

Accepted Answer

A) electric charges produce electric fields. 
B) moving electric charges produce magnetic fields. 
C) changing electric fields produce magnetic fields. 
D) changing magnetic fields produce electric fields. 
A) electric charges produce electric fields. 
B) moving electric charges produce magnetic fields. 
C) changing electric fields produce magnetic fields. 
D) changing magnetic fields produce electric fields.

Question 10

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 11

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 12

An RLC circuit has resistance R0, inductance L0, and capacitance C0.If the resistance value is now doubled, which values of inductance and capacitance will result in the same resonant frequency as before.

Accepted Answer

A) 2L0, 2C0 
B) L0/2, C0/2 
C) 2L0, C0/2 
D) 2L0, C0 
A) 2L0, 2C0 
B) L0/2, C0/2 
C) 2L0, C0/2 
D) 2L0, C0

Question 13

The primary winding of an electric train transformer has 400 turns, and the secondary has 50.If the input voltage is 120 V(rms), what is the output voltage?

Accepted Answer

A) 480 V 
B) 60 V 
C) 15 V 
D) 10 V 
A) 480 V 
B) 60 V 
C) 15 V 
D) 10 V

Question 14

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

Accepted Answer

A) 1/3 
B) 1.0 
C) 1.73 
D) 3.0 
A) 1/3 
B) 1.0 
C) 1.73 
D) 3.0

Question 15

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

Accepted Answer

A) 1/3 
B) 1.0 
C) 3.0 
D) Information is insufficient to determine answer. 
A) 1/3 
B) 1.0 
C) 3.0 
D) Information is insufficient to determine answer.

Question 16

A resistor, inductor, and capacitor are connected in series, each with an effective (rms) voltage of 65 V, 140 V, and 80 V, respectively.What is the magnitude of the phase angle in this circuit?

Accepted Answer

A) 22$\degree$ 
B) 28$\degree$ 
C) 37$\degree$ 
D) 43$\degree$ 
A) 22$\degree$ 
B) 28$\degree$ 
C) 37$\degree$ 
D) 43$\degree$

Question 17

A 200-W resistor is connected in series with a 10-µF capacitor and a 60-Hz, 120-V (rms) line voltage.If electrical energy costs 5.0¢ per kWh, how much does it cost to leave this circuit connected for 24 hours?

Accepted Answer

A) 62¢ 
B) 31¢ 
C) 5.2¢ 
D) 3.1¢ 
A) 62¢ 
B) 31¢ 
C) 5.2¢ 
D) 3.1¢

Question 18

The Earth is 1.49 * 1011 m from the Sun.If the solar radiation at the top of the Earth's atmosphere is 1 340 W/m2, what is the total power output of the Sun?

Accepted Answer

A) 7.48 * 1027 W 
B) 2.34 * 1030 W 
C) 6.62 * 1026 W 
D) 3.74 * 1026 W 
A) 7.48 * 1027 W 
B) 2.34 * 1030 W 
C) 6.62 * 1026 W 
D) 3.74 * 1026 W

Question 19

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 20

A radio wave signal, which transmits at a frequency of 7.20 MHz, has what wavelength? (c = 3.00 * 108 m/s)

Accepted Answer

A) 41.7 m 
B) 4.17 m 
C) 28.8 m 
D) 2.4 * 10-2 m 
A) 41.7 m 
B) 4.17 m 
C) 28.8 m 
D) 2.4 * 10-2 m

Exam 21: Alternating Current Circuits and Electromagnetic Waves

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

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

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

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?

An AC voltage source, with a peak output of 200 V, is connected to a 50-W resistor.What is the rate of energy dissipated due to heat in the resistor?

In an RLC series circuit the capacitive reactance is 24 W.If the AC frequency doubles, what will be the resulting capacitive reactance?

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

Maxwell developed his theory of electromagnetism by combining previous discoveries.He added his own original hypothesis that:

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

Microwave radiation is useful in which of the following?

An RLC circuit has resistance R0, inductance L0, and capacitance C0.If the resistance value is now doubled, which values of inductance and capacitance will result in the same resonant frequency as before.

The primary winding of an electric train transformer has 400 turns, and the secondary has 50.If the input voltage is 120 V(rms), what is the output voltage?

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

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

A resistor, inductor, and capacitor are connected in series, each with an effective (rms) voltage of 65 V, 140 V, and 80 V, respectively.What is the magnitude of the phase angle in this circuit?

A 200-W resistor is connected in series with a 10-µF capacitor and a 60-Hz, 120-V (rms) line voltage.If electrical energy costs 5.0¢ per kWh, how much does it cost to leave this circuit connected for 24 hours?

The Earth is 1.49 * 1011 m from the Sun.If the solar radiation at the top of the Earth's atmosphere is 1 340 W/m2, what is the total power output of the Sun?

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?

A radio wave signal, which transmits at a frequency of 7.20 MHz, has what wavelength? (c = 3.00 * 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

An RLC circuit has resistance R₀, inductance L₀, and capacitance C₀.If the resistance value is now doubled, which values of inductance and capacitance will result in the same resonant frequency as before.

The Earth is 1.49 * 10¹¹m from the Sun.If the solar radiation at the top of the Earth's atmosphere is 1 340 W/m², what is the total power output of the Sun?

A radio wave signal, which transmits at a frequency of 7.20 MHz, has what wavelength? (c = 3.00 * 10⁸ m/s)