Question 1

A beam of light is propagating in the x direction. The electric-field vector

Accepted Answer

A)  can oscillate in any arbitrary direction in space. 
B)  must oscillate in the z direction. 
C)  must oscillate in the yz plane. 
D)  must oscillate in the x direction. 
E)  must have a steady component in the x direction.

Question 2

An astronaut is stranded in space a distance of 50 m from her spaceship. She carries a 5-kW laser gun. If the total mass of the astronaut, space suit, and laser gun is 90 kg, approximately how long will it take her to reach her ship if she points the laser gun directly away from it?

Accepted Answer

A)  3.2 h 
B)  6.5 h 
C)  13 h 
D)  2.3 * 104 h 
E)  3.2 * 104 s

Question 3

Light that has a wavelength of 600 nm has a frequency of

Accepted Answer

A)  5.0*1015 Hz 
B)  5.0 * 1014 Hz 
C)  5.0 * 106 Hz 
D)  1.2* 105 Hz 
E)  1.2 * 1014 Hz

Question 4

A 60-W light bulb emits spherical electromagnetic waves uniformly in all directions. If 50% of the power input to such a light bulb is emitted as electromagnetic radiation, what is the maximum value of the electric field at a distance of 2.0 m from the light bulb?

Accepted Answer

A)  43 V/m 
B)  0.11 mV/m 
C)  21 V/m 
D)  60 V/m 
E)  30 V/m

Question 5

A 60-W light bulb emits spherical electromagnetic waves uniformly in all directions. If 50% of the power input to such a light bulb is emitted as electromagnetic radiation, what is the maximum value of the magnetic field at a distance of 2.0 m from the light bulb?

Accepted Answer

A)  71 nT 
B)  0.35 $\mu$T 
C)  0.14$\mu$T 
D)  0.20 $\mu$T 
E)  0.10 $\mu$T

Question 6

The detection of radio waves can be accomplished with either a dipole antenna or a loop antenna. The dipole antenna detects the _____ of the wave, and the loop antenna detects the _____ field of the wave.

Accepted Answer

A)  electric field; electric 
B)  electric field; magnetic 
C)  magnetic field; magnetic 
D)  magnetic field; electric 
E)  electric and magnetic fields; electric

Question 7

How long does it take light to travel across the width of a Pb nucleus of radius 7.1 fm?

Accepted Answer

A)  2.4 *10-23 s 
B)  1.2 * 10-23 s 
C)  2.4 * 10-20 s 
D)  4.7 *10-23 s 
E)  none of the above

Question 8

An AC voltage, V = 20 V sin (1000 rad/s t) is applied across a capacitor of capacitance C = 40 $\mu$F. The capacitor is made of two circular plate each of radius r = 5 cm. What is the peak magnetic field at the circumference of the capacitor?

Accepted Answer

A)  1.2 $\mu$T 
B)  1.6.2 $\mu$T 
C)  3.2 $\mu$T 
D)  72 $\mu$T 
E)  None of these is correct.

Question 9

The rms value of the magnitude of the magnetic field in an electromagnetic wave is
Brms = 0.378 T. The average energy density of this wave is approximately

Accepted Answer

A)  114 kJ/m3  
B)  28.4 kJ/m3  
C)  31.8 kJ/m3  
D)  67.8 kJ/m3  
E)  56.9 kJ/m3

Question 10

The electric field in a region of space varies according to
E = (1.25 N/C) sin 1500t
Where t is in seconds. The maximum displacement current through a 2.00-m2 area perpendicular to E is approximately

Accepted Answer

A)  3.32 nA 
B)  13.3 nA 
C)  66.4 nA 
D)  16.6 nA 
E)  33.2 nA

Question 11

The wavelength of a 150-MHz television signal is approximately

Accepted Answer

A)  1.0 m 
B)  1.5 m 
C)  2.0 m 
D)  2.0 cm 
E)  50 cm

Question 12

Which of the following statements is true?

Accepted Answer

A)  Both the  and the  components of an electromagnetic wave satisfy the wave equation. 
B)  The phase of a wave traveling in the negative z direction is kz + $ \omega $t. 
C)  The speed of an electromagnetic wave traveling in a vacuum is given by $\varepsilon$0$\mu$0)-1/2. 
D)  The magnitude of  is greater than the magnitude of  by a factor of c. 
E)  All of these statements are true.

Question 13

A 60-W light bulb emits spherical electromagnetic waves uniformly in all directions. If 50% of the power input to such a light bulb is emitted as electromagnetic radiation, what is the radiation pressure at a distance of 2.0 m from the light bulb?

Accepted Answer

A)  50 nPa 
B)  2.0 nPa 
C)  8.0 nPa 
D)  16 nPa 
E)  4.0 nPa

Question 14

An AC voltage is applied across a capacitor. Which figure best represents the magnetic field between the capacitor?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  5

Question 15

The intensity of a laser beam is 450 W/m2. What is the rms value of the electric field of this laser beam? (The permittivity of free space$\in$0 = 8.85 * 10-12 C2/N · m2 and the permeability of free space µ0 = 4 $\pi$0 * 10-7 N/A2.)

Accepted Answer

A)  1.7 * 105 V/m 
B)  5.8 *102 V/m 
C)  3.4 *105 V/m 
D)  4.1 * 102 V/m 
E)  1.3 * 103 V/m

Question 16

Maxwell generalized Ampère's law to read  from which the displacement current is defined as

Accepted Answer

A)   
B)   
C)   
D)   
E)

Question 17

The nearest star to us, Alpha Centauri, is 4.30 light-years away. What is this distance in kilometers?

Accepted Answer

A)  4.1 * 1010 km 
B)  4.1 * 1013 km 
C)  4.1 *1016 km 
D)  6.8 * 1011 km 
E)  6.8 * 1014 km

Question 18

The polar plot of the intensity of electromagnetic radiation from an electric-dipole antenna shows that the intensity is

Accepted Answer

A)  a maximum at $\theta$ = 0º. 
B)  a minimum at $\theta$ = 90º. 
C)  a maximum at $\theta$= 90º. 
D)  independent of the angle $\theta$. 
E)  None of these is correct.

Question 19

Arrange the following types of electromagnetic radiation in order of increasing wavelength: gamma rays, infrared light, ultraviolet light, visible light.

Accepted Answer

A)  Gamma rays are not electromagnetic radiation. 
B)  gamma rays, infrared, visible, ultraviolet 
C)  gamma rays, ultraviolet, visible, infrared 
D)  visible, ultraviolet, infrared, gamma rays 
E)  ultraviolet, visible, infrared, gamma rays

Question 20

Electromagnetic waves are produced when

Accepted Answer

A)  free electric charges accelerate. 
B)  conduction electrons move with a constant drift velocity in a conductor. 
C)  a conductor moves with constant velocity through a magnetic field. 
D)  electrons bound to atoms and molecules make transitions to higher energy states. 
E)  All of these are correct.

Exam 10: Maxwells Equations and Electromagnetic Waves

A beam of light is propagating in the x direction. The electric-field vector

An astronaut is stranded in space a distance of 50 m from her spaceship. She carries a 5-kW laser gun. If the total mass of the astronaut, space suit, and laser gun is 90 kg, approximately how long will it take her to reach her ship if she points the laser gun directly away from it?

Light that has a wavelength of 600 nm has a frequency of

A 60-W light bulb emits spherical electromagnetic waves uniformly in all directions. If 50% of the power input to such a light bulb is emitted as electromagnetic radiation, what is the maximum value of the electric field at a distance of 2.0 m from the light bulb?

A 60-W light bulb emits spherical electromagnetic waves uniformly in all directions. If 50% of the power input to such a light bulb is emitted as electromagnetic radiation, what is the maximum value of the magnetic field at a distance of 2.0 m from the light bulb?

The detection of radio waves can be accomplished with either a dipole antenna or a loop antenna. The dipole antenna detects the _ of the wave, and the loop antenna detects the _ field of the wave.

How long does it take light to travel across the width of a Pb nucleus of radius 7.1 fm?

An AC voltage, V = 20 V sin (1000 rad/s t) is applied across a capacitor of capacitance C = 40 $\mu$ F. The capacitor is made of two circular plate each of radius r = 5 cm. What is the peak magnetic field at the circumference of the capacitor?

The rms value of the magnitude of the magnetic field in an electromagnetic wave is B_rms = 0.378 T. The average energy density of this wave is approximately

The electric field in a region of space varies according to E = (1.25 N/C) sin 1500t Where t is in seconds. The maximum displacement current through a 2.00-m² area perpendicular to E is approximately

The wavelength of a 150-MHz television signal is approximately

Which of the following statements is true?

A 60-W light bulb emits spherical electromagnetic waves uniformly in all directions. If 50% of the power input to such a light bulb is emitted as electromagnetic radiation, what is the radiation pressure at a distance of 2.0 m from the light bulb?

An AC voltage is applied across a capacitor. Which figure best represents the magnetic field between the capacitor?

The intensity of a laser beam is 450 W/m². What is the rms value of the electric field of this laser beam? (The permittivity of free space $\in$ ₀ = 8.85 * 10^-12 C²/N · m² and the permeability of free space µ₀ = 4 $\pi$ 0 * 10^-7 N/A².)

Maxwell generalized Ampère's law to read from which the displacement current is defined as

The nearest star to us, Alpha Centauri, is 4.30 light-years away. What is this distance in kilometers?

Arrange the following types of electromagnetic radiation in order of increasing wavelength: gamma rays, infrared light, ultraviolet light, visible light.

Electromagnetic waves are produced when

Exam 10: Maxwells Equations and Electromagnetic Waves

A beam of light is propagating in the x direction. The electric-field vector

An astronaut is stranded in space a distance of 50 m from her spaceship. She carries a 5-kW laser gun. If the total mass of the astronaut, space suit, and laser gun is 90 kg, approximately how long will it take her to reach her ship if she points the laser gun directly away from it?

Light that has a wavelength of 600 nm has a frequency of

A 60-W light bulb emits spherical electromagnetic waves uniformly in all directions. If 50% of the power input to such a light bulb is emitted as electromagnetic radiation, what is the maximum value of the electric field at a distance of 2.0 m from the light bulb?

A 60-W light bulb emits spherical electromagnetic waves uniformly in all directions. If 50% of the power input to such a light bulb is emitted as electromagnetic radiation, what is the maximum value of the magnetic field at a distance of 2.0 m from the light bulb?

The detection of radio waves can be accomplished with either a dipole antenna or a loop antenna. The dipole antenna detects the _____ of the wave, and the loop antenna detects the _____ field of the wave.

How long does it take light to travel across the width of a Pb nucleus of radius 7.1 fm?

An AC voltage, V = 20 V sin (1000 rad/s t) is applied across a capacitor of capacitance C = 40 μ\muμ F. The capacitor is made of two circular plate each of radius r = 5 cm. What is the peak magnetic field at the circumference of the capacitor?

The rms value of the magnitude of the magnetic field in an electromagnetic wave is Brms = 0.378 T. The average energy density of this wave is approximately

The electric field in a region of space varies according to E = (1.25 N/C) sin 1500t Where t is in seconds. The maximum displacement current through a 2.00-m2 area perpendicular to E is approximately

The wavelength of a 150-MHz television signal is approximately

Which of the following statements is true?

A 60-W light bulb emits spherical electromagnetic waves uniformly in all directions. If 50% of the power input to such a light bulb is emitted as electromagnetic radiation, what is the radiation pressure at a distance of 2.0 m from the light bulb?

An AC voltage is applied across a capacitor. Which figure best represents the magnetic field between the capacitor?

The intensity of a laser beam is 450 W/m2. What is the rms value of the electric field of this laser beam? (The permittivity of free space ∈\in∈ 0 = 8.85 * 10-12 C2/N · m2 and the permeability of free space µ0 = 4 π\piπ 0 * 10-7 N/A2.)

Maxwell generalized Ampère's law to read from which the displacement current is defined as

The nearest star to us, Alpha Centauri, is 4.30 light-years away. What is this distance in kilometers?

The polar plot of the intensity of electromagnetic radiation from an electric-dipole antenna shows that the intensity is

Arrange the following types of electromagnetic radiation in order of increasing wavelength: gamma rays, infrared light, ultraviolet light, visible light.

Electromagnetic waves are produced when

The detection of radio waves can be accomplished with either a dipole antenna or a loop antenna. The dipole antenna detects the _ of the wave, and the loop antenna detects the _ field of the wave.

An AC voltage, V = 20 V sin (1000 rad/s t) is applied across a capacitor of capacitance C = 40 $\mu$ F. The capacitor is made of two circular plate each of radius r = 5 cm. What is the peak magnetic field at the circumference of the capacitor?

The rms value of the magnitude of the magnetic field in an electromagnetic wave is B_rms = 0.378 T. The average energy density of this wave is approximately

The electric field in a region of space varies according to E = (1.25 N/C) sin 1500t Where t is in seconds. The maximum displacement current through a 2.00-m² area perpendicular to E is approximately

The intensity of a laser beam is 450 W/m². What is the rms value of the electric field of this laser beam? (The permittivity of free space $\in$ ₀ = 8.85 * 10^-12 C²/N · m² and the permeability of free space µ₀ = 4 $\pi$ 0 * 10^-7 N/A².)