Question 1

Why do polarizing sunglasses work to reduce glare?

Accepted Answer

A) They don't; this is just a marketing ploy 
B) They reduce the amount of light entering your eyes 
C) Light reflected from horizontal surfaces tends to be horizontally polarized, so the sunglasses' vertical polarization cuts the glare 
D) Light reflected from horizontal surfaces tends to be vertically polarized, so the sunglasses' horizontal polarization cuts the glare 
E) Light reflected from horizontal surfaces tends to be horizontally polarized, so the sunglasses' horizontal polarization cuts the glare 
A) They don't; this is just a marketing ploy 
B) They reduce the amount of light entering your eyes 
C) Light reflected from horizontal surfaces tends to be horizontally polarized, so the sunglasses' vertical polarization cuts the glare 
D) Light reflected from horizontal surfaces tends to be vertically polarized, so the sunglasses' horizontal polarization cuts the glare 
E) Light reflected from horizontal surfaces tends to be horizontally polarized, so the sunglasses' horizontal polarization cuts the glare C

Question 2

Which of the following is NOT true for electromagnetic waves?

Accepted Answer

A) they consist of changing electric and magnetic fields 
B) they travel at different speeds in vacuum, depending on their frequency 
C) they transport energy 
D) they transport momentum 
E) they can be reflected 
A) they consist of changing electric and magnetic fields 
B) they travel at different speeds in vacuum, depending on their frequency 
C) they transport energy 
D) they transport momentum 
E) they can be reflected B

Question 3

Polarization experiments provide evidence that light is:

Accepted Answer

A) a longitudinal wave 
B) a stream of particles 
C) a transverse wave 
D) some type of wave 
E) nearly monochromatic 
A) a longitudinal wave 
B) a stream of particles 
C) a transverse wave 
D) some type of wave 
E) nearly monochromatic C

Question 4

As used in the laws of reflection and refraction, the "normal" direction is:

Accepted Answer

A) any convenient direction 
B) tangent to the interface 
C) along the incident ray 
D) perpendicular to the electric field vector of the light 
E) perpendicular to the interface 
A) any convenient direction 
B) tangent to the interface 
C) along the incident ray 
D) perpendicular to the electric field vector of the light 
E) perpendicular to the interface

Question 5

Three polarizing sheets are placed in a stack with the polarizing directions of the first and third perpendicular to each other.What angle should the polarizing direction of the middle sheet make with the polarizing direction of the first sheet to obtain maximum transmitted intensity when unpolarized light is incident on the stack?

Accepted Answer

A) 0° 
B) 30$\degree$ 
C) 45$\degree$ 
D) 60$\degree$ 
E) 90$\degree$ 
A) 0° 
B) 30$\degree$ 
C) 45$\degree$ 
D) 60$\degree$ 
E) 90$\degree$

Question 6

For linearly polarized light the plane of polarization is:

Accepted Answer

A) perpendicular to both the direction of polarization and the direction of propagation 
B) perpendicular to the direction of polarization and parallel to the direction of propagation 
C) parallel to the direction of polarization and perpendicular to the direction of propagation 
D) parallel to both the direction of polarization and the direction of propagation 
E) none of the above 
A) perpendicular to both the direction of polarization and the direction of propagation 
B) perpendicular to the direction of polarization and parallel to the direction of propagation 
C) parallel to the direction of polarization and perpendicular to the direction of propagation 
D) parallel to both the direction of polarization and the direction of propagation 
E) none of the above

Question 7

The theoretical upper limit for the frequency of electromagnetic waves is:

Accepted Answer

A) just slightly greater than that of red light 
B) just slightly less than that of blue light 
C) the greatest x-ray frequency 
D) none of the above (there is no upper limit) 
E) none of the above (but there is an upper limit) 
A) just slightly greater than that of red light 
B) just slightly less than that of blue light 
C) the greatest x-ray frequency 
D) none of the above (there is no upper limit) 
E) none of the above (but there is an upper limit)

Question 8

The order of increasing wavelength for blue (b), green (g), red (r), and yellow (y)light is:

Accepted Answer

A) r, y, g, b 
B) r, g, y, b 
C) g, y, b, r 
D) b, g, y, r 
E) b, y, g, r 
A) r, y, g, b 
B) r, g, y, b 
C) g, y, b, r 
D) b, g, y, r 
E) b, y, g, r

Question 9

When an electromagnetic wave meets a reflecting surface, the direction taken by the reflected wave is determined by:

Accepted Answer

A) the material of the reflecting surface 
B) the angle of incidence 
C) the index of the medium 
D) the intensity of the wave 
E) the wavelength 
A) the material of the reflecting surface 
B) the angle of incidence 
C) the index of the medium 
D) the intensity of the wave 
E) the wavelength

Question 10

The speed of light in vacuum is about:

Accepted Answer

A) 1100 ft/s 
B) 93 * 106 mi/s 
C) 6 * 1023 m/s 
D) 3 * 1010 cm/s 
E) 186,000 mph 
A) 1100 ft/s 
B) 93 * 106 mi/s 
C) 6 * 1023 m/s 
D) 3 * 1010 cm/s 
E) 186,000 mph

Question 11

Radio waves differ from visible light waves in that radio waves:

Accepted Answer

A) travel slower 
B) have a higher frequency 
C) travel faster 
D) have a lower frequency 
E) require a material medium 
A) travel slower 
B) have a higher frequency 
C) travel faster 
D) have a lower frequency 
E) require a material medium

Question 12

If the electric field in a plane electromagnetic wave is given by Emsin[(3 * 106 m-1 x)- $ \omega $t], the value of $ \omega $is:

Accepted Answer

A) 0.01 rad/s 
B) 10 rad/s 
C) 100 rad/s 
D) 9 * 1014 rad/s 
E) 9 *1016 rad/s 
A) 0.01 rad/s 
B) 10 rad/s 
C) 100 rad/s 
D) 9 * 1014 rad/s 
E) 9 *1016 rad/s

Question 13

A point source emits electromagnetic energy at a rate of 100 W.The intensity 10 m from the source is:

Accepted Answer

A) 10 W/m2 
B) 1.6 W/m2 
C) 1.0 W/m2 
D) 0.080 W/m2 
E) 0.024W/m2 
A) 10 W/m2 
B) 1.6 W/m2 
C) 1.0 W/m2 
D) 0.080 W/m2 
E) 0.024W/m2

Question 14

An unpolarized beam of light has intensity I0.It is incident on two ideal polarizing sheets.The angle between the axes of polarization of these sheets is $\theta$.Find $\theta$if the emerging light has intensity I0/4:

Accepted Answer

A) sin-1(1/2) 
B) sin-1(1/) 
C) cos-1(1/2) 
D) cos-1(1/) 
E) tan-1(1/4) 
A) sin-1(1/2) 
B) sin-1(1/) 
C) cos-1(1/2) 
D) cos-1(1/) 
E) tan-1(1/4)

Question 15

A company claims to have developed material that absorbs light energy without a transfer of momentum.Such material is:

Accepted Answer

A) impossible 
B) possible, but very expensive 
C) inexpensive and already in common use 
D) in use by NASA but is not commercially available 
E) a breakthrough in high technology 
A) impossible 
B) possible, but very expensive 
C) inexpensive and already in common use 
D) in use by NASA but is not commercially available 
E) a breakthrough in high technology

Question 16

Select the correct statement:

Accepted Answer

A) ultraviolet light has a longer wavelength than infrared 
B) blue light has a higher frequency than X rays 
C) radio waves have a higher frequency than gamma rays 
D) gamma rays have a higher frequency than infrared waves 
E) electrons are a type of electromagnetic wave 
A) ultraviolet light has a longer wavelength than infrared 
B) blue light has a higher frequency than X rays 
C) radio waves have a higher frequency than gamma rays 
D) gamma rays have a higher frequency than infrared waves 
E) electrons are a type of electromagnetic wave

Question 17

A vertical automobile radio antenna is sensitive to electric fields that are polarized:

Accepted Answer

A) horizontally 
B) in circles around the antenna 
C) vertically 
D) normal to the antenna in the forward direction 
E) none of the above 
A) horizontally 
B) in circles around the antenna 
C) vertically 
D) normal to the antenna in the forward direction 
E) none of the above

Question 18

The index of refraction of a certain glass is 1.50.The sine of the critical angle for total internal reflection at a glass-air interface is:

Accepted Answer

A) 0.50 
B) 0.67 
C) 0.75 
D) 1.00 
E) 1.50 
A) 0.50 
B) 0.67 
C) 0.75 
D) 1.00 
E) 1.50

Question 19

Visible light has a frequency of about:

Accepted Answer

A) 5 * 1018 Hz 
B) 5* 1016 Hz 
C) 5 *1014 Hz 
D) 5 * 1012 Hz 
E) 5 * 1010 Hz 
A) 5 * 1018 Hz 
B) 5* 1016 Hz 
C) 5 *1014 Hz 
D) 5 * 1012 Hz 
E) 5 * 1010 Hz

Question 20

Consider radio waves (r), visible light (v), infrared (i), X rays (x), and ultraviolet (u).In order of increasing frequency, they are:

Accepted Answer

A) r, v, i, x, u 
B) r, i, v, u, x 
C) i, r, v, u, x 
D) x, u, v, i, r 
E) r, i, v, x, u 
A) r, v, i, x, u 
B) r, i, v, u, x 
C) i, r, v, u, x 
D) x, u, v, i, r 
E) r, i, v, x, u

Exam 33: Electromagnetic Waves

Why do polarizing sunglasses work to reduce glare?

Which of the following is NOT true for electromagnetic waves?

Polarization experiments provide evidence that light is:

As used in the laws of reflection and refraction, the "normal" direction is:

For linearly polarized light the plane of polarization is:

The theoretical upper limit for the frequency of electromagnetic waves is:

The order of increasing wavelength for blue (b), green (g), red (r), and yellow (y)light is:

When an electromagnetic wave meets a reflecting surface, the direction taken by the reflected wave is determined by:

The speed of light in vacuum is about:

Radio waves differ from visible light waves in that radio waves:

If the electric field in a plane electromagnetic wave is given by Emsin[(3 * 106 m-1 x)- ω \omega ω t], the value of ω \omega ω is:

A point source emits electromagnetic energy at a rate of 100 W.The intensity 10 m from the source is:

An unpolarized beam of light has intensity I0.It is incident on two ideal polarizing sheets.The angle between the axes of polarization of these sheets is θ\thetaθ .Find θ\thetaθ if the emerging light has intensity I0/4:

A company claims to have developed material that absorbs light energy without a transfer of momentum.Such material is:

Select the correct statement:

A vertical automobile radio antenna is sensitive to electric fields that are polarized:

The index of refraction of a certain glass is 1.50.The sine of the critical angle for total internal reflection at a glass-air interface is:

Visible light has a frequency of about:

Consider radio waves (r), visible light (v), infrared (i), X rays (x), and ultraviolet (u).In order of increasing frequency, they are:

Measurement

Motion Along a Straight Line

Vector

Motion in Two and Three Dimensions

Force and Motion I

Force and Motion II

Kinetic Energy and Work

Potential Energy and Conservation of Energy

Center of Mass and Linear Momentum

Rotation

Rolling, Torque, and Angular Momentum

Equilibrium and Elasticity

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Temperature, Heat, and the First Law of Thermodynamics

The Kinetic Theory of Gases

Entropy and the Second Law of Thermodynamics

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Magnetic Fields Due to Currents

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Electromagnetic Oscillations and Alternating Current

Maxwells Equations; Magnetism of Matter

Images

Interference

Diffraction

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Photons and Matter Waves

More About Matter Waves

All About Atoms

Conduction of Electricity in Solids

Nuclear Physics

Energy From the Nucleus

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Filters

If the electric field in a plane electromagnetic wave is given by E_msin[(3 * 10⁶ m^-1 x)- $\omega$ t], the value of $\omega$ is:

An unpolarized beam of light has intensity I₀.It is incident on two ideal polarizing sheets.The angle between the axes of polarization of these sheets is $\theta$ .Find $\theta$ if the emerging light has intensity I₀/4: