OPTICS PRACTICE PROBLEMS

OPTICS REVIEW PROBLEMS

1 When a light wave enters a new medium and is refracted, there must be a change in the light wave’s(1) color (3) period(2) frequency (4) speed

2 The speed of light in a piece of plastic is 2.00 ×108 meters per second. What is the absolute index of refraction of this plastic?(1) 1.00 (3) 1.33(2) 0.670 (4) 1.501

3 An electromagnetic wave traveling through a vacuum has a wavelength of 1.5 ×10–1 meter.What is the period of this electromagnetic wave?(1) 5.0 ×10–10 s (3) 4.5 ×107 s(2) 1.5 ×10–1 s (4) 2.0 ×109 s

4 A ray of light (f = 5.09 ×1014 Hz) traveling in air strikes a block of sodium chloride at an angle of incidence of 30°. What is the angle of refraction for the light ray in the sodium chloride?(1) 19° (3) 40°(2) 25° (4) 49°

5 The speed of a ray of light traveling through a substance having an absolute index of refraction of 1.1 is(1) 1.1 ×108 m/s (3) 3.0 ×108 m/s(2) 2.7 ×108 m/s (4) 3.3 ×108 m/s

6 Which quantity is equivalent to the product of the absolute index of refraction of water and the speed of light in water?(1) wavelength of light in a vacuum(2) frequency of light in water(3) sine of the angle of incidence(4) speed of light in a vacuum

7 Radio waves and gamma rays traveling in space have the same(1) frequency (3) period(2) wavelength (4) speed

8 The spreading of a wave into the region behind an obstruction is called(1) diffraction (3) reflection(2) absorption (4) refraction

9 A beam of light travels through medium X with a speed of 1.80 ×108 meters per second.Calculate the absolute index of refraction of medium X. [Show all work, including the equation and substitution with units.]

10 The speed of light (f = 5.09 ×1014 Hz) in a transparent material is 0.75 times its speed in air.

The absolute index of refraction of the material is approximately(1) 0.75 (3) 2.3(2) 1.3 (4) 4.0

11 The diagram below shows a ray of light passing from medium X into air.

What is the absolute index of refraction of medium X?(1) 0.500 (3) 1.73(2) 2.00 (4) 0.577

12 What occurs when light passes from water into flint glass?(1) Its speed decreases, its wavelength becomes shorter, and its frequency remains the same.(2) Its speed decreases, its wavelength becomes shorter, and its frequency increases.(3) Its speed increases, its wavelength becomes longer, and its frequency remains the same.(4) Its speed increases, its wavelength becomes longer, and its frequency decreases.

13 The diagram below shows straight wave fronts passing through an opening in a barrier.

This wave phenomenon is called(1) reflection (3) polarizaton(2) refraction (4) diffraction

14 The speed of light in a material is 2.50 ×108

meters per second. What is the absolute index of

refraction of the material?(1) 1.20 (3) 7.50(2) 2.50 (4) 0.833

15 The diagram below shows parallel rays of light incident on an irregular surface.

Which phenomenon of light is illustrated by the diagram?1 diffraction 3 regular reflection2 refraction 4 diffuse reflection

16 What is the speed of light in a medium having an absolute index of refraction of 2.3?(1) 0.77 ×108 m/s (3) 1.5 ×108

m/s(2) 1.3 ×108

m/s (4) 2.3 ×108 m/s

17 The diagram below shows a ray of light passing through two media.

When the wave travels from medium A into medium B, its speed1 decreases2 increases3 remains the same

18 Experiments performed with light indicate that light exhibits1 particle properties, only2 wave properties, only3 both particle and wave properties4 neither particle nor wave properties

19 What is the energy of a quantum of light having a frequency of 6.0 ×1014 hertz?(1) 1.6 ×10–19 J (3) 3.0 ×108 J(2) 4.0 ×10–19 J (4) 5.0 ×10–7 J

20 The speed of light in a piece of plastic is 2.00 ×108 meters per second. What is the absolute index of refraction of this plastic?(1) 1.00 (3) 1.33(2) 0.670 (4) 1.50

21 A ray of light (f = 5.09 ×1014 Hz) traveling in air strikes a block of sodium chloride at an angle of incidence of 30°. What is the angle of refraction for the light ray in the sodium chloride?(1) 19° (3) 40°(2) 25° (4) 49°

22 The speed of a ray of light traveling through a substance having an absolute index of refraction of 1.1 is(1) 1.1 ×108 m/s (3) 3.0 ×108 m/s(2) 2.7 ×108 m/s (4) 3.3 ×108 m/s

23 Which phenomenon provides evidence that light has a wave nature?(1) emission of light from an energy-level transition in a hydrogen atom(2) diffraction of light passing through a narrow opening(3) absorption of light by a black sheet of paper(4) reflection of light from a mirror

24 Which diagram best represents the path taken by a ray of monochromatic light as it passes from air through the materials shown?

25 What is the speed of a ray of light (f = 5.09 ×1014

hertz) traveling through a block of sodium chloride?(1) 1.54 ×108

m/s (3) 3.00 ×108 m/s

(2) 1.95 ×108 m/s (4) 4.62 ×108

m/s

26 Which phenomenon occurs when an object absorbs wave energy that matches the object’s natural frequency?(1) reflection (3) resonance(2) diffraction (4) interference

27 A ray of monochromatic light (f = 5.09 ×1014

hertz) in air is incident at an angle of 30° on a boundary with corn oil. What is the angle of refraction, to the nearest degree, for this light ray in the corn oil?(1) 6° (3) 30°(2) 20° (4) 47°

28 Which ray diagram best represents the phenomenon of refraction?

29 A ray of light (f = 5.09 ×1014 Hz) traveling in air is incident at an angle of 40° on an air-crown glass interface as shown below.

What is the angle of refraction for this light ray?(1) 25° (3) 40°(2) 37° (4) 78°

30 The speed of light in a piece of plastic is 2.00 ×108 meters per second. What is the absolute index of refraction of this plastic?(1) 1.00 (3) 1.33(2) 0.670 (4) 1.50

ANALYTICAL PROBLEMS

A. Base your answers to questions 1 and 2 on the information below.A ray of monochromatic light (f = 5.09 × 1014 Hz) passes from air into Lucite at an angle of incidence of 30.˚.

1 Calculate the angle of refraction in the Lucite. [Show all work, including the equation and substitution with units.]

2 Using a protractor and straightedge draw the refracted ray in the Lucite.

B.A ray of light (f = 5.09 ×1014 Hz) is incident on the boundary between air and an unknown material X at an angle of incidence of 55°, as shown. The absolute index of refraction of material X is 1.66.

1 Identify a substance of which material X may be composed.

2 Determine the speed of this ray of light in material X.

3 Calculate the angle of refraction of the ray of light in material X. [Show all work, including the equation and substitution with units.]

4 On the above diagram, use a straightedge and protractor to draw the refracted ray of light in material X.

C.A ray of monochromatic light of frequency5.09 ×1014 hertz is traveling from water into medium X. The angle of incidence in water is45° and the angle of refraction in medium X is 29°, as shown.

1 Calculate the absolute index of refraction of medium X. [Show all work, including the equation and substitution with units.]2 Medium X is most likely what material?

D. Base your answers to questions 1 through 3 on the information and diagram below.A ray of light passes from air into a block of transparent material X as shown in the diagram below.

1 Measure the angles of incidence and refraction to the nearest degree for this light ray at the air into material X boundary.

2 Calculate the absolute index of refraction of material X. [Show all work, including the equation and substitution with units.]

3 The refracted light ray is reflected from the material X–air boundary at point P. Using a protractor and straightedge, on the above diagram, draw the reflected ray from point P.

E. Base your answers to questions 1 through 3 on the diagram below which shows a ray of monochromatic light (f = 5.09 ×1014 hertz) passing through a flint glass prism.

1 Calculate the angle of refraction (in degrees) of the light ray as it enters the air from the flint glass prism.[Show all calculations, including the equation and substitution with units.]

2 Using a protractor and a straightedge construct the refracted light ray in the air on the above diagram.

3 What is the speed of the light ray in flint glass?(1) 5.53 ×10–9

m/s (3) 3.00 ×108 m/s

(2) 1.81 ×108 m/s (4) 4.98 ×108

m/s

F.A ray of monochromatic light having a frequency of 5.09 ×1014 hertz is incident on an interface of air and corn oil at an angle of 35° as shown. The ray is transmitted through parallel layers of corn oil and glycerol and is then reflected from the surface of a plane mirror, located below and parallel to the glycerol layer. The ray then emerges from the corn oil back into the air at point P.

1 Calculate the angle of refraction of the light ray as it enters the corn oil from air. [Show all work, including the equation and the substitution with units.]

2 Explain why the ray does not bend at the corn oil-glycerol interface.

3 On the above diagram, use a protractor and straightedge to construct the refracted ray representing the light emerging at point P into air.

G. Base your answers to questions 1 through 4 on the diagram below, which shows a light ray (f = 5.09 ×1014 Hz) in air, incident on a boundary with fused quartz. At the boundary, part of the light is refracted and part of the light is reflected.

1 Using a protractor, measure the angle of incidence of the light ray at the air-fused quartz boundary.

2 Calculate the angle of refraction of the incident light ray. [Show all work, including the equation and substitution with units.]

3 Using a protractor and straightedge construct the refracted light ray in the fused quartz on the above diagram.

4 Using a protractor and straightedge construct the reflected light ray on above the diagram.