Question 1

The light intensity 10 m from a point source is 1000 W/m2. The intensity 100 m from the same source is:

Accepted Answer

A)  1000 W/m2 
B)  100 W/m2 
C)  10 W/m2 
D)  1 W/m2 
E)  0.1 W/m2 
A)  1000 W/m2 
B)  100 W/m2 
C)  10 W/m2 
D)  1 W/m2 
E)  0.1 W/m2 C

Question 2

Radio waves of wavelength 3 cm have a frequency of:

Accepted Answer

A)  1 MHz 
B)  9 MHz 
C)  100 MHz 
D)  900 MHz 
E)  10,000 MHz 
A)  1 MHz 
B)  9 MHz 
C)  100 MHz 
D)  900 MHz 
E)  10,000 MHz E

Question 3

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 E

Question 4

The sun is about 1.5 * 1011 m away. The time for light to travel this distance is about:

Accepted Answer

A)  4.5 * 1019 s 
B)  8 s 
C)  8 min 
D)  8 hr 
E)  8 yr 
A)  4.5 * 1019 s 
B)  8 s 
C)  8 min 
D)  8 hr 
E)  8 yr

Question 5

The diagram shows the passage of a ray of light from air into a substance X. The index of refraction of X is:

Accepted Answer

A)  0.53 
B)  0.82 
C)  1.2 
D)  1.9 
E)  3.0 
A)  0.53 
B)  0.82 
C)  1.2 
D)  1.9 
E)  3.0

Question 6

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 7

If nwater = 1.33 and nglass = 1.50, then total internal reflection at an interface between this glass and water:

Accepted Answer

A)  occurs whenever the light goes from glass to water 
B)  occurs whenever the light goes from water to glass 
C)  may occur when the light goes from glass to water 
D)  may occur when the light goes from water to glass 
E)  can never occur at this interface 
A)  occurs whenever the light goes from glass to water 
B)  occurs whenever the light goes from water to glass 
C)  may occur when the light goes from glass to water 
D)  may occur when the light goes from water to glass 
E)  can never occur at this interface

Question 8

Light with an intensity of 1 kW/m2 falls normally on a surface and is completely reflected. The radiation pressure is:

Accepted Answer

A)  1 kPa 
B)  3 * 1011 Pa 
C)  1.7 *10-6 Pa 
D)  3.3 * 10-6 Pa 
E)  6.7 * 10-6 Pa 
A)  1 kPa 
B)  3 * 1011 Pa 
C)  1.7 *10-6 Pa 
D)  3.3 * 10-6 Pa 
E)  6.7 * 10-6 Pa

Question 9

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

Question 10

The time for a radar signal to travel to the Moon and back, a one-way distance of about 3.8 *108 m, is:

Accepted Answer

A)  1.3 s 
B)  2.5 s 
C)  8 s 
D)  8 min 
E)  1 * 106 s 
A)  1.3 s 
B)  2.5 s 
C)  8 s 
D)  8 min 
E)  1 * 106 s

Question 11

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

Accepted Answer

A)  0° 
B)  30  $\degree$ 
C)  45  $\degree$ 
D)  60  $\degree$ 
E)  all angles allow light to pass through 
A)  0° 
B)  30  $\degree$ 
C)  45  $\degree$ 
D)  60  $\degree$ 
E)  all angles allow light to pass through

Question 12

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 13

Light from any ordinary source (such as a flame) is usually:

Accepted Answer

A)  unpolarized 
B)  plane polarized 
C)  circularly polarized 
D)  elliptically polarized 
E)  monochromatic 
A)  unpolarized 
B)  plane polarized 
C)  circularly polarized 
D)  elliptically polarized 
E)  monochromatic

Question 14

Evidence that electromagnetic waves carry momentum is:

Accepted Answer

A)  the tail of a comet points away from the sun 
B)  electron flow through a wire generates heat 
C)  a charged particle in a magnetic field moves in a circular orbit 
D)  heat can be generated by rubbing two sticks together 
E)  the Doppler effect 
A)  the tail of a comet points away from the sun 
B)  electron flow through a wire generates heat 
C)  a charged particle in a magnetic field moves in a circular orbit 
D)  heat can be generated by rubbing two sticks together 
E)  the Doppler effect

Question 15

An electromagnetic wave is transporting energy in the negative y direction. At one point and one instant the magnetic field is in the positive x direction. The electric field at that point and instant is:

Accepted Answer

A)  positive y direction 
B)  negative y direction 
C)  positive z direction 
D)  negative z direction 
E)  negative x direction 
A)  positive y direction 
B)  negative y direction 
C)  positive z direction 
D)  negative z direction 
E)  negative x direction

Question 16

Light with an intensity of 1 kW/m2 falls normally on a surface with an area of 1 cm2 and is completely reflected. The force of the radiation on the surface is:

Accepted Answer

A)  3.3* 10-11 N 
B)  1.7 *10-10 N 
C)  3.3* 10-10 N 
D)  6.7*10-10 N 
E)  1.0 *10-4 N 
A)  3.3* 10-11 N 
B)  1.7 *10-10 N 
C)  3.3* 10-10 N 
D)  6.7*10-10 N 
E)  1.0 *10-4 N

Question 17

Light of uniform intensity shines perpendicularly on a totally absorbing surface, fully illuminating the surface. If the area of the surface is decreased:

Accepted Answer

A)  the radiation pressure increases and the radiation force increases 
B)  the radiation pressure increases and the radiation force decreases 
C)  the radiation pressure stays the same and the radiation force increases 
D)  the radiation pressure stays the same and the radiation force decreases 
E)  the radiation pressure decreases and the radiation force decreases 
A)  the radiation pressure increases and the radiation force increases 
B)  the radiation pressure increases and the radiation force decreases 
C)  the radiation pressure stays the same and the radiation force increases 
D)  the radiation pressure stays the same and the radiation force decreases 
E)  the radiation pressure decreases and the radiation force decreases

Question 18

The relation n1sin $\theta$1 = n2 sin$\theta$2 which applies as a ray of light strikes an interface between two media, is known as:

Accepted Answer

A)  Gauss' law 
B)  Snell's law 
C)  Faraday's law 
D)  Cole's law 
E)  law of sines 
A)  Gauss' law 
B)  Snell's law 
C)  Faraday's law 
D)  Cole's law 
E)  law of sines

Question 19

When light travels from medium X to medium Y as shown:

Accepted Answer

A)  both the speed and the frequency decrease 
B)  both the speed and the frequency increase 
C)  both the speed and the wavelength decrease 
D)  both the speed and the wavelength increase 
E)  both the wavelength and the frequency are unchanged 
A)  both the speed and the frequency decrease 
B)  both the speed and the frequency increase 
C)  both the speed and the wavelength decrease 
D)  both the speed and the wavelength increase 
E)  both the wavelength and the frequency are unchanged

Question 20

The dimensions of are:

Accepted Answer

A)  J/m2 
B)  J/s 
C)  W/s 
D)  W/m2 
E)  J/m3 
A)  J/m2 
B)  J/s 
C)  W/s 
D)  W/m2 
E)  J/m3

Exam 33: Electromagnetic Waves

The light intensity 10 m from a point source is 1000 W/m2. The intensity 100 m from the same source is:

Radio waves of wavelength 3 cm have a frequency of:

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

The sun is about 1.5 * 1011 m away. The time for light to travel this distance is about:

The diagram shows the passage of a ray of light from air into a substance X. The index of refraction of X is:

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:

If nwater = 1.33 and nglass = 1.50, then total internal reflection at an interface between this glass and water:

Light with an intensity of 1 kW/m2 falls normally on a surface and is completely reflected. The radiation pressure is:

Why do polarizing sunglasses work to reduce glare?

The time for a radar signal to travel to the Moon and back, a one-way distance of about 3.8 *108 m, is:

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

Light from any ordinary source (such as a flame) is usually:

Evidence that electromagnetic waves carry momentum is:

An electromagnetic wave is transporting energy in the negative y direction. At one point and one instant the magnetic field is in the positive x direction. The electric field at that point and instant is:

Light with an intensity of 1 kW/m2 falls normally on a surface with an area of 1 cm2 and is completely reflected. The force of the radiation on the surface is:

Light of uniform intensity shines perpendicularly on a totally absorbing surface, fully illuminating the surface. If the area of the surface is decreased:

The relation n1sin θ\thetaθ 1 = n2 sin θ\thetaθ 2 which applies as a ray of light strikes an interface between two media, is known as:

When light travels from medium X to medium Y as shown:

The dimensions of 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

Gravitation

Fluids

Oscillations

Waves I

Waves II

Temperature, Heat, and the First Law of Thermodynamics

The Kinetic Theory of Gases

Entropy and the Second Law of Thermodynamics

Electric Charge

Electric Fields

Gauss Law

Electric Potential

Capacitance

Current and Resistance

Circuits

Magnetic Fields

Magnetic Fields Due to Currents

Induction and Inductance

Electromagnetic Oscillations and Alternating Current

Maxwells Equations; Magnetism of Matter

Images

Interference

Diffraction

Relativity

Photons and Matter Waves

More About Matter Waves

All About Atoms

Conduction of Electricity in Solids

Nuclear Physics

Energy From the Nucleus

Quarks, Leptons, and the Big Bang

Filters

The light intensity 10 m from a point source is 1000 W/m². The intensity 100 m from the same source is:

The sun is about 1.5 * 10¹¹ m away. The time for light to travel this distance is about:

The diagram shows the passage of a ray of light from air into a substance X. The index of refraction of X is: $The diagram shows the passage of a ray of light from air into a substance X. The index of refraction of X is:$

If n_water = 1.33 and n_glass = 1.50, then total internal reflection at an interface between this glass and water:

Light with an intensity of 1 kW/m² falls normally on a surface and is completely reflected. The radiation pressure is:

The time for a radar signal to travel to the Moon and back, a one-way distance of about 3.8 *10⁸ m, is:

Light with an intensity of 1 kW/m² falls normally on a surface with an area of 1 cm² and is completely reflected. The force of the radiation on the surface is:

The relation n₁sin $\theta$ ₁ = n₂ sin $\theta$ ₂ which applies as a ray of light strikes an interface between two media, is known as: