Question 1

The energy density of an electromagnetic wave in free space is

Accepted Answer

A) entirely in the electric field. 
B) entirely in the magnetic field. 
C) 1/4 in the electric field and 3/4 in the magnetic field. 
D) 1/4 in the magnetic field and 3/4 in the electric field. 
E) equally divided between the magnetic and the electric fields. 
A) entirely in the electric field. 
B) entirely in the magnetic field. 
C) 1/4 in the electric field and 3/4 in the magnetic field. 
D) 1/4 in the magnetic field and 3/4 in the electric field. 
E) equally divided between the magnetic and the electric fields.

Question 2

Which one of the following types of electromagnetic wave travels through space the fastest?

Accepted Answer

A) radio waves 
B) infrared 
C) ultraviolet 
D) microwaves 
E) They all travel through space at the same speed. 
A) radio waves 
B) infrared 
C) ultraviolet 
D) microwaves 
E) They all travel through space at the same speed.

Question 3

What is the wavelength used by a radio station that broadcasts at a frequency of 920 kHz? (c = 3.00 × 108 m/s)

Accepted Answer

A) 22.6 m 
B) 226 m 
C) 326 m 
D) 175 m 
E) 276 m 
A) 22.6 m 
B) 226 m 
C) 326 m 
D) 175 m 
E) 276 m

Question 4

A radar receiver indicates that a pulse return as an echo in 20 μs after it was sent.How far away is the reflecting object? (c = 3.0 × 108 m/s)

Accepted Answer

A) 1.5 km 
B) 3.0 km 
C) 6.0 km 
D) 9.0 km 
A) 1.5 km 
B) 3.0 km 
C) 6.0 km 
D) 9.0 km

Question 5

For a beam of light,the direction of polarization is defined as

Accepted Answer

A) the beam's direction of travel. 
B) the direction of the $\vec { E }$ field's vibration. 
C) the direction of the $\vec { B }$ field's vibration. 
D) the direction that is perpendicular to both the $\vec { E }$ field and $\vec { B }$ field vectors. 
A) the beam's direction of travel. 
B) the direction of the $\vec { E }$ field's vibration. 
C) the direction of the $\vec { B }$ field's vibration. 
D) the direction that is perpendicular to both the $\vec { E }$ field and $\vec { B }$ field vectors.

Question 6

Unpolarized light of intensity I0 passed through an ideal polarizing sheet with its polarizing axis at the 12 o'clock position and then through a second ideal sheet with its polarizing axis at the 1 o'clock position.What is the intensity of the emerging light in terms of I0?

Accepted Answer

Question 7

Radiation of a single frequency reaches the upper atmosphere of the earth with an intensity of 1350 W/m2.What is the maximum value of the $\vec { E }$ field associated with this radiation? (c = 3.00 × 108 m/s,μ0 = 4π × 10-7 T ∙ m/A,ε0 = 8.85 × 10-12 C2/N ∙ m2)

Accepted Answer

A) 675.0 V/m 
B) 1604 V/m 
C) 1400 V/m 
D) 1350 V/m 
E) 1010 V/m 
A) 675.0 V/m 
B) 1604 V/m 
C) 1400 V/m 
D) 1350 V/m 
E) 1010 V/m

Question 8

For a certain electromagnetic wave in a vacuum,at one instant the $\vec { E }$ field vector points in the +z direction while the $\vec { B }$ field vector points in the +x direction,as shown in the figure.In what direction is this wave traveling?

Accepted Answer

A) +x 
B) -x 
C) +y 
D) -y 
E) +z 
A) +x 
B) -x 
C) +y 
D) -y 
E) +z

Question 9

A 7.55 × $10^{14}$ Hz electromagnetic wave travels in carbon tetrachloride with a speed of 2.05 ×108 m/s.What is the wavelength of the wave in this material?

Accepted Answer

A) 272 nm 
B) 301 nm 
C) 338 nm 
D) 361 nm 
E) 397 nm 
A) 272 nm 
B) 301 nm 
C) 338 nm 
D) 361 nm 
E) 397 nm

Question 10

The frequency of a microwave signal is 9.76 GHz.What is its wavelength? (c = 3.00 × 108 m/s)

Accepted Answer

A) 3.07 cm 
B) 2.07 cm 
C) 1.07 cm 
D) 5.07 cm 
E) 4.07 cm 
A) 3.07 cm 
B) 2.07 cm 
C) 1.07 cm 
D) 5.07 cm 
E) 4.07 cm

Question 11

A radio station broadcasts at a frequency of 80 MHz.How far from the transmitter will this signal travel in 67 ms? (c = 3.0 × 108 m/s)

Accepted Answer

A) 60 × 106 m 
B) 67 m 
C) 40 km 
D) 80 km 
E) 20 × 106 m 
A) 60 × 106 m 
B) 67 m 
C) 40 km 
D) 80 km 
E) 20 × 106 m

Question 12

How far does a beam of light travel in 2.0 ms? (c = 3.0 × 108 m/s)

Accepted Answer

A) 6.0 × 105 m 
B) 0.66 × 105 m 
C) 90 m 
D) 70 m 
E) 60 m 
A) 6.0 × 105 m 
B) 0.66 × 105 m 
C) 90 m 
D) 70 m 
E) 60 m

Question 13

Which one of the following lists gives the correct order of the electromagnetic spectrum from low to high frequencies?

Accepted Answer

A) radio waves, infrared, microwaves, ultraviolet, visible, x-rays, gamma rays 
B) radio waves, ultraviolet, x-rays, microwaves, infrared, visible, gamma rays 
C) radio waves, microwaves, infrared, visible, ultraviolet, x-rays, gamma rays 
D) radio waves, microwaves, visible, x-rays, infrared, ultraviolet, gamma rays 
E) radio waves, infrared, x-rays, microwaves, ultraviolet, visible, gamma rays 
A) radio waves, infrared, microwaves, ultraviolet, visible, x-rays, gamma rays 
B) radio waves, ultraviolet, x-rays, microwaves, infrared, visible, gamma rays 
C) radio waves, microwaves, infrared, visible, ultraviolet, x-rays, gamma rays 
D) radio waves, microwaves, visible, x-rays, infrared, ultraviolet, gamma rays 
E) radio waves, infrared, x-rays, microwaves, ultraviolet, visible, gamma rays

Question 14

A light source radiates 60.0 W of single-wavelength sinusoidal light uniformly in all directions.What is the amplitude of the electric field of this light at a distance of 0.400 m from the bulb? (ε0 = 8.85 × 10-12 C2/N ∙ m2,μ0 = 4π × 10-7 T ∙ m/A,c = 3.00 × 108 m/s)

Accepted Answer

A) 162 N/C 
B) 212 N/C 
C) 82.1 N/C 
D) 150 N/C 
E) 52.9 N/C 
A) 162 N/C 
B) 212 N/C 
C) 82.1 N/C 
D) 150 N/C 
E) 52.9 N/C

Question 15

Which of the following statements about electromagnetic waves in a vacuum are true? (There could be more than one correct choice.)

Accepted Answer

A) The higher-frequency travel faster than the lower-frequency waves. 
B) The higher-frequency waves have shorter wavelengths than the lower-frequency waves. 
C) The wavelengths of the visible waves are some of the longest electromagnetic waves. 
D) The wavelengths of the visible waves are some of the shortest electromagnetic waves. 
E) The $\vec { E }$ field vector is always at right angles to the $\vec { B }$ field vector. 
A) The higher-frequency travel faster than the lower-frequency waves. 
B) The higher-frequency waves have shorter wavelengths than the lower-frequency waves. 
C) The wavelengths of the visible waves are some of the longest electromagnetic waves. 
D) The wavelengths of the visible waves are some of the shortest electromagnetic waves. 
E) The $\vec { E }$ field vector is always at right angles to the $\vec { B }$ field vector.

Question 16

Find Brewster's angle for light in air that is reflected from the top of a water surface.The index of refraction of the water is 1.33.

Accepted Answer

A) 53.1° 
B) 36.9° 
C) 56.3° 
D) 60.2° 
E) 90.0° 
A) 53.1° 
B) 36.9° 
C) 56.3° 
D) 60.2° 
E) 90.0°

Question 17

Unpolarized light passes through three ideal polarizing filters.The first filter is oriented with a horizontal transmission axis,the second one has its transmission axis at 30° from the horizontal,and the third filter has a vertical transmission axis.What percent of the light gets through this combination?

Accepted Answer

A) 9.4% 
B) 91% 
C) 50% 
D) 0% 
E) 33% 
A) 9.4% 
B) 91% 
C) 50% 
D) 0% 
E) 33%

Question 18

The critical angle for an air-glass interface is 42.6°.A light ray in air hits the interface,and the reflected ray is 100% polarized.What is the angle of refraction for that ray?

Accepted Answer

A) 47.4° 
B) 55.9° 
C) 24.3° 
D) 65.7° 
E) 34.1° 
A) 47.4° 
B) 55.9° 
C) 24.3° 
D) 65.7° 
E) 34.1°

Question 19

A light source radiates 60.0 W of single-wavelength sinusoidal light uniformly in all directions.What is the average intensity of the light from this bulb at a distance of 0.400 m from the bulb?

Accepted Answer

A) 14.9 W/m2 
B) 37.2 W/m2 
C) 27.4 W/m2 
D) 11.9 W/m2 
E) 29.8 W/m2 
A) 14.9 W/m2 
B) 37.2 W/m2 
C) 27.4 W/m2 
D) 11.9 W/m2 
E) 29.8 W/m2

Exam 25: Electromagnetic Waves

The energy density of an electromagnetic wave in free space is

Which one of the following types of electromagnetic wave travels through space the fastest?

What is the wavelength used by a radio station that broadcasts at a frequency of 920 kHz? (c = 3.00 × 108 m/s)

A radar receiver indicates that a pulse return as an echo in 20 μs after it was sent.How far away is the reflecting object? (c = 3.0 × 108 m/s)

For a beam of light,the direction of polarization is defined as

Unpolarized light of intensity I0 passed through an ideal polarizing sheet with its polarizing axis at the 12 o'clock position and then through a second ideal sheet with its polarizing axis at the 1 o'clock position.What is the intensity of the emerging light in terms of I0?

Radiation of a single frequency reaches the upper atmosphere of the earth with an intensity of 1350 W/m2.What is the maximum value of the E⃗\vec { E }E field associated with this radiation? (c = 3.00 × 108 m/s,μ0 = 4π × 10-7 T ∙ m/A,ε0 = 8.85 × 10-12 C2/N ∙ m2)

For a certain electromagnetic wave in a vacuum,at one instant the E⃗\vec { E }E field vector points in the +z direction while the B⃗\vec { B }B field vector points in the +x direction,as shown in the figure.In what direction is this wave traveling?

A 7.55 × 101410^{14}1014 Hz electromagnetic wave travels in carbon tetrachloride with a speed of 2.05 ×108 m/s.What is the wavelength of the wave in this material?

The frequency of a microwave signal is 9.76 GHz.What is its wavelength? (c = 3.00 × 108 m/s)

A radio station broadcasts at a frequency of 80 MHz.How far from the transmitter will this signal travel in 67 ms? (c = 3.0 × 108 m/s)

How far does a beam of light travel in 2.0 ms? (c = 3.0 × 108 m/s)

Which one of the following lists gives the correct order of the electromagnetic spectrum from low to high frequencies?

A light source radiates 60.0 W of single-wavelength sinusoidal light uniformly in all directions.What is the amplitude of the electric field of this light at a distance of 0.400 m from the bulb? (ε0 = 8.85 × 10-12 C2/N ∙ m2,μ0 = 4π × 10-7 T ∙ m/A,c = 3.00 × 108 m/s)

Which of the following statements about electromagnetic waves in a vacuum are true? (There could be more than one correct choice.)

Find Brewster's angle for light in air that is reflected from the top of a water surface.The index of refraction of the water is 1.33.

The critical angle for an air-glass interface is 42.6°.A light ray in air hits the interface,and the reflected ray is 100% polarized.What is the angle of refraction for that ray?

A light source radiates 60.0 W of single-wavelength sinusoidal light uniformly in all directions.What is the average intensity of the light from this bulb at a distance of 0.400 m from the bulb?

Introduction

Kinematics: Motion in One Dimension

Newtonian Mechanics

Applying Newtons Laws

Circular Motion

Impulse and Linear Momentum

Work and Energy

Extended Bodies at Rest

Rotational Motion

Gases

Static Fluids

Fluids in Motion

First Law of Thermodynamics

Second Law of Thermodynamics

Electric Charge force and Energy

The Electric Field

Dc Circuits

Magnetism

Electromagnetic Induction

Vibrational Motion

Mechanical Waves

Reflection and Refraction

Mirrors and Lenses

Wave Optics

Special Relativity

Quantum Optics

Atomic Physics

Nuclear Physics

Particle Physics

Filters

What is the wavelength used by a radio station that broadcasts at a frequency of 920 kHz? (c = 3.00 × 10⁸ m/s)

A radar receiver indicates that a pulse return as an echo in 20 μs after it was sent.How far away is the reflecting object? (c = 3.0 × 10⁸ m/s)

Unpolarized light of intensity I₀ passed through an ideal polarizing sheet with its polarizing axis at the 12 o'clock position and then through a second ideal sheet with its polarizing axis at the 1 o'clock position.What is the intensity of the emerging light in terms of I₀?

Radiation of a single frequency reaches the upper atmosphere of the earth with an intensity of 1350 W/m².What is the maximum value of the $\vec { E }$ field associated with this radiation? (c = 3.00 × 10⁸ m/s,μ₀ = 4π × 10^-7 T ∙ m/A,ε₀ = 8.85 × 10^-12 C²/N ∙ m²)

A 7.55 × $10^{14}$ Hz electromagnetic wave travels in carbon tetrachloride with a speed of 2.05 ×10⁸ m/s.What is the wavelength of the wave in this material?

The frequency of a microwave signal is 9.76 GHz.What is its wavelength? (c = 3.00 × 10⁸ m/s)

A radio station broadcasts at a frequency of 80 MHz.How far from the transmitter will this signal travel in 67 ms? (c = 3.0 × 10⁸ m/s)

How far does a beam of light travel in 2.0 ms? (c = 3.0 × 10⁸ m/s)

A light source radiates 60.0 W of single-wavelength sinusoidal light uniformly in all directions.What is the amplitude of the electric field of this light at a distance of 0.400 m from the bulb? (ε₀ = 8.85 × 10^-12 C²/N ∙ m²,μ₀ = 4π × 10^-7 T ∙ m/A,c = 3.00 × 10⁸ m/s)