eu1c3 By Adel Khamis

Unit one -120- Chapter Three

Multiple choice questions

Evaluation book:

1. A thin prism of refractive index 1.5 and angle 4, the angle of

deviation equals: [4 – 3 – 2 – 1](1)

2. The angle of a thin prism is 6 and the angle of deviation is 3 of an

incident ray, the refractive index of such prism is [1.8 – 1.7 – 1.6 – 1.5](2)

3. A light ray falls on the interface between two media at an angle of

incidence of 60, it refracts by an angle 45. The relative refractive index between

the first medium and second medium is [2.44 – 1.44 – 1.22 – 1.5]

4. A light ray transfers from a medium to air, if the critical angle is 30,

so the absolute refractive index of such medium equals: [ - ½ - 2 – 1 ]

5. Knowing that absolute refractive index of benzene is 1.5, and

absolute refractive index of flint glass 1.65, then the relative refractive index

between benzene and flint glass equals [0.91 – 1.1 – 1.25 – 1.5]

6. The relative refractive index between flint glass and benzene

(according to the information given in the previous question), equals: [1.65 – 1.5 –

1.1 – 0.91]

7. When a ray of light falls with an angle of incidence on a glass

rectangle 60, if the absolute refractive index of glass = then the angle of

refraction equals: [90 – 60 – 30 – 45]

8. When a ray of light falls on the

mirror A in a direction parallel to mirror B (as

shown in figure) the reflected ray falls on the

mirror B with an angle of incidence equals to

[90 – 60 – 30 – 0]

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9. In the previous figure the reflected

beam at the mirror B falls once more on the mirror

A with an angle of incidence equals to [60 – 45 –

30 – 0]

10. Trace the light ray in the following

figure.

11. If the ray of light falls normally on one face of a triangular prism of

refractive index = 1.5, it emerges from the prism

within emergence angle equals to [90-60 – 0 –

30]

12. If the ray of light falls normally on one side of a glass triangle prism

as shown in the figure and if the refractive index of the prism is 1.5 the incident ray

on the face corresponding to the right angle inside the

prism will be: [emerge with an angle 45 – emerge with

an angle 60 – emerge with an angle 90 – be totally

reflected]

13. In the previous figure if the refractive

index of the4 prism is 1.4, the incident ray on the face corresponding to the right

angle will: [be totally reflected – emerge with an angle 60 – emerge with an angle

82 – emerge tangent to this face]

14. A narrow, parallel beam of light

meets the face YZ of a glass prism XYZ at normal

incidence, the angles of the prism being as marked

in the diagram. If the critical angle of glass is 42,

which of the following statements is not true?

a) The beam cross the air glass boundary yz

without deviation.

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60


b) The angle of incidence at the face XY is 60.

c) The beam undergoes total internal reflection at the face XY.

d) A beam emerges from the face XZ.

e) The beam undergoes total internal reflection at face XZ.

15. In one medium a wave has a frequency f1 wavelength 1 and speed

c1 the wave passes from this medium into another, where its speed is 2/3 c1, in the

second medium the:

a) frequency is still f1 and the wavelength is still 1

b) frequency is still f1 but the wavelength is 2/3 1

c) frequency is still f1 and the wavelength is still 3/2 1

d) wavelength is still 1 but the frequency is 2/3 f1

e) wavelength is still 1 but the frequency is 3/2 f1

Previous exams:

16. (Egypt 2002) When light passes from a denser optical medium to a less dense

medium, then the maximum value of the angle of refraction in the less dense

medium is [42 - 45 - 90 - 180]

17. (Egypt 95) Total internal reflection takes place when light ray falls from optically

denser medium to optically rarer medium when the angle of incidence is [less

than the critical angle – more than the critical angle – equal to the critical angle]

18. (Egypt 2000) The mirage is produced by (diffraction – total reflection –

interference) of white light.

Exercises 2008/2009


Directions: for each of the questions below one or more of the

responses given are correct. Decide which of the responses is (are)

correct. Then choose:

A: if 1, 2 and3 are all correct.

B: if1 and 2 are correct.

C: if 2 and 3 are correct.

D: if 1 only is correct.

E: if 3 only is correct

Evaluation book:

1. If a ray of light is deviated when crossing a plane boundary separating two

transparent media:

a) The angle of refraction is doubled when the angle of incidence is

doubled.

b) The angle between the normal to the boundary and the incident ray

is always greater than the angle between the normal and the

refracted ray.

c) The refracted ray always lies in the same place as the normal and

the incident ray.

2. If the refractive index of the glass of a glass block is 1.5 then:

a) The speed of light in the air = 1.5 x the speed of light in the glass block.

b) The angle of incidence in the air = 1.5 x the angle of refraction in the glass

block.

c) The apparent depth of the glass block = 1.5 the real depth of the glass

block.

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Give reasons

Evaluation book:

1. (Egypt 96) The absolute refractive index of a medium is always

greater than one(3).

2. (August 96) The reflection prism is preferred to metallic mirror in

some optical equipment(4).

3. (Egypt 2002) In Young’s double slit experiment the interference

fringes become more clearly as the distance between the two slits decreases.

4. (Egypt 92, August 97) When white light falls on a triangular prism,

adjusted in the minimum deviation position, the emerged ray is deviated into

different colored rays known as spectrum(5).

5. The relative refractive index between two media may be less than

unity.

6. The rectangular glass block does not disperse white light to its

seven colors.

7. (Egypt 98) The optical fibers may be used in the transport of

light(6).

8. The occurrence of mirage in deserts(7).

9. As the light ray passes through a narrow double slit, there are

interference fringes (bright and dark) on a white screen placed at a suitable

distance.

10. The red color has the minimum deviation while the violet light has

maximum deviation in the prism.

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Additional questions:

11. The beam of light falls perpendicular on the interface between two

media is un-deviated.

12. The red color has the minimum deviation while the violet light has

maximum deviation in the prism.

What is meant by

Evaluation book:

1. The absolute refractive index of water = 4/3.

2. The absolute refractive index of glass =3/2

3. The relative refractive index from water to glass = 9/8

4. Angular dispersion in thin prism =0.2

5. The dispersive power in triangular prism = 0.02

6. The angle of deviation in triangular prism = 30

7. The critical angle between glass and air =42

8. What is meant by optical fibers? And what are their

applications?

Previous exams:

9. (Egypt 2002) The absolute refractive index off a

medium = 1.4

10. (Egypt 98) The dispersive power of a prism = 0.02.

11. (August 97) The refractive index of light between the

glass and water is 0.6.

12. (Egypt 97, August 2000) The critical angle between

the glass and air is 30.

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13. (Egypt 94) Relative refractive index between two

medium (1) and (2) = 1: 1

14. (Egypt 2002) The angular dispersion in a thin prism =

0.2

15. (Egypt 97) The angle between the produced extended

parts of the incident ray and the emergent ray in a triangular prism.

Compare between each of the following

Evaluation book:

1. What is the different between the critical angle and the angle of

deviation in prism?


2. Reflecting prism and refracting prism.

3. Reflection and total reflection.

Which of the following statements are right and which are wrong? Rewrite the incorrect statements in

a correct form

Previous Exams

1. (Egypt 97) In the case of minimum deviation in a glass triangular prism: the angle

of incidence = the angle of deviation.

2. (Egypt 93) In minimum deviation angle of incidence = angle of emergence =

angle of deviation.

3. (Egypt 93) Relative refractive index between two media is always smaller than

one.

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4. The absolute refractive index of a medium = the reciprocal of the sine of its

critical angle when the light transfers from medium to air.

5. Angular deviation of spectrum = αb –αr.

6. The refractive index 1n2 = n1 . n2.

7. The absolute refractive index of a medium is the ratio of the velocity of light in

this medium to the velocity of light in air.

8. Mirage, reflecting prism and optical fibers are application of total reflection of

light.

9. The angle of deviation increases gradually by increasing the angle of incidence

till min. deviation and after that the angle of deviation increases again by the

increasing of angle of incidence.

Mention one function only for each of the following

Previous exams:

1. (Egypt 2000) The double slits in Young’s experiment for studying the

interference of light waves.

2. (Egypt 98, August 99) The totally reflecting prism.

3. (August 99, august 2000) Optical fiber.

What happens with mention the reason for each of the following when…?

Previous exams:

1. (August 2001) Incident a ray of light by an angle equal to zero on the one of the

perpendicular side of an isosceles triangular glass prism until go out from the

another face knowing that the critical angle of glass = 42

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Define each of the following physical quantities and write the unit used to measure each of them if

available

Previous exams:

1- (Egypt 90, Egypt 2001) Critical angle.

2- (Egypt 90) Absolute refractive index of a medium.

3- (August 2001) The coherent sources in light.

Complete the following statements

Previous exams:

1. (August 96) The relative refractive index between a medium (a)

and a medium (b) is equal to the ratio between the absolute refractive index of the

medium (……….) to the absolute refractive index of the medium (……….)

2. (Egypt 93) Angle of deviation in a triangular glass prism is

……….

3. (Egypt 96) If the absolute refractive index for diamond is 2.4 and

for glass is 1.6 the critical angle for diamond is …………… the critical angle for

glass.


4. The absolute refractive index is greater than … because…..

5. The absolute refractive index of a medium is the ratio of the

velocity of light in …….... to ………

6. The angle of deviation in thin prism = …………..

7. The angle of prism is determined using the relation ……………

8. The distance between two successive similar fringes is equal to

……………..

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9. The ray, which falls perpendicular to the interface between two

mediums, transfers …….... This is because its angle of incidence =

………………..

10. The refractive index between two mediums is the ratio between

….. to … and also it is the ratio between ………... to ………. of the second

medium.

11. When the angle of incidence increases from minimum. The angle

of deviation …… to arrive to its ………….then it called …………. and then it

…………...

Prove that:

1- The angle of deviation in a thin prism α = A

( n-1).

2- In triangular prism, prove that the relation

between α, 1, θ2. and the relation between A , 1 , ф2.

Write down only (without explanation) two factors that each of the

following depends on:

1. (Egypt 95, Egypt 2000) The deviation angle in a thin prism.

Essay questions:

1- Explain Young’s experiment.

2-

Two mirrors x and y are fixed such that

the angle between their reflecting

surfaces is 45. A light ray ab is

incident on x, find the angle of

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reflection from x and the incident angle on y. With drawing determine the

direction of the ray.

3- (August 99) You have an equilateral glass

triangular prism. Explain with drawing an experiment to trace the path of a ray

through the prism. Indicate on the drawing the angle of the prism, the angle of

incidence, the angle of emergence and the angle of deviation of the ray. Write

down one relation between these

angles.

4- As

shown in the figure: a ray ab falls on a

mirror (X), find the angle of reflection

at the mirror (Y) complete the

drawing. Determine the direction of

the reflected ray at the mirror (Y)

comment on the final result.

5- A

ray falls on a mirror (X) as shown in the

figure; find the angle of reflection at the

mirror (Y). Complete the drawing.

Determine the direction of the reflected

ray at the mirror (Y). Comment on the

final result.

4. (Egypt 99) A light ray is incident perpendicular to

one side of a triangular prism of refractive index

1.5 as shown in figure. Trace the path of the light

ray inside the prism in your answer paper, and

then find its angle of emergence from the prism.

Exercises 2008/2009


[48 35’]

5. (August 98) Deduce for a thin prism the relation

between the angle of deviation () its angle (A) and the refractive index (n) of its

material.

6. (Egypt 2001) Explain the scientific basic on which

the function of the optical fibers.

7. When a ray of

light falls on the mirror A in a direction parallel

to mirror B (as shown in figure). Find the

incidence angle on the mirror B and complete

the diagram.

8. (Egypt Aug 2002) In the figure; an equilateral triangular glass prism of refractive

index 1.5. A light ray is incident normal to the side (ac).

Complete the path of the light ray until it emerges from the prism and give

reason for that.

Find the value of the emergence angle of the light ray.

Find the value of the acute angle between the direction of the incident ray and

that of the emergent ray.(8)

9. (Egypt 97) Trace by drawing the path of a ray of

light shown in the figure through a glass triangular prism with an angle 90 this ray

is incident in a perpendicular direction on one side of the right angle. Given that

the two sides of the right angle are equals and that the critical angle between the

glass and air is 42. Find also the angle of emergence.

Write down the scientific term for each of the following:

(Egypt 97) Illuminated and dark regions resulting from the superposition

of two waves of the same frequency, amplitude, and are in the same phase.

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1. (Egypt 2002) The following “graph” represent a

physical relations. Mention the relation used and write

what is the slope equals to:

Problems

1. Find the refractive index of a prism has refractive angle 6 and angle of

deviation 3.

[1.5]

2. Light ray falls on surface of water with angle of 30. Find the angle

between reflected ray and refracted ray if (n) of water = 1.4.

[129]

3. Light ray fall with angle 60 on a glass cube of length 4 cm and refractive

index 1.5, find the shift resultant in the emergent ray due to the lass cube.

[4.1 cm]

4. A light ray falls on the interface between two media at an angle of

incidence of 60. It refracts by an angle 45. Find the refractive index between the

first medium and second medium.

[1.225]

5. A light ray transfers from a medium to air, if the critical angle is 30. Find

the absolute refractive index of such medium.

[2]

6. An object 20 cm longs is placed vertically in front of a vertical plane

mirror at a distance of 10 cm find:

a) The position of the image.

b) The length of the image.

c) Magnification of the image.

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d) Characteristics of the image.

[10 cm, 20 cm, -1, virtual, erect, equal]

7. Knowing that absolute refractive index of benzene is 1.5, and absolute

refractive index of flint glass 1.65; find the relative refractive index between

benzene and flint glass, and the relative refractive index between flint glass and

benzene.

[1.1, 0.91]

8. If the refractive index of water and glass are 1.4 and 1.6 respectively, the

velocity of light in air is 3 x 108 m/s. Calculate:

a) The velocity of light in water.

b) The critical angle for water relative to air.

c) The relative refractive index between glass and water.

[2.14x108, 45.6, 0.875]

9. A light ray falls in the interface between water and air by an angle 45

determine the direction of the reflecting and refracting rays, knowing that the

refractive index of water = 1.4.

[45, 30 20’]

10. In Young’s double slit experiment monochromatic light of wavelength

6000 angstrom. The distance between 2 successive fringes on the screen is 1.5 cm

& the distance between the slits & the screen is 1.2 m. find the slit separation.

[4.8x10-5m]

11. The separating distance between the two slits in Young’s experiment is

0.00015 meter and the distance between the slits and the screen on which the

fringes are formed is 0.75m. Given that the spacing between 2 successive

Exercises 2008/2009


illuminated fringes is 0.003m. Calculate the wavelength of the used

monochromatic light.

[6x10-7m]

12. A ray of light falls at one side of a rectangular glass block of refractive

index (root 2). Find both of the angle of incidence and refraction if the emergent

angle is 45

[45, 30]

13. A ray of light falls from air on the surface of a glass block so that it

makes an angle 30 with the surface of the block. Find the perpendicular distance

between the point of incidence and the point of emergence. Given that the distance

between them is 2 cm. and the refractive index of glass is root 3.

[1.732 cm]

14. A ray of light falls at an angle 60 on the surface of water, locate the

direction of reflected and refracted rays and the angle between them where n of

water equals 1.33

[60, 40.63, 79.37]

15. Calculate the frequency of the used light in Young’s experiment, if the

distance separating the two slits is 0.0015m and the distance between the double

slits and the screen is 0.75 m and the distance between two successive illuminated

fringes is 0.0002 m. given that the velocity of light 3 x 108 m/s.

[7.5x1014Hz]

16. If the angle of minimum deviation is 30 for a triangular prism whose

sides are equal. Find the refractive index of the prism, incident angle and emergent

angle of the ray in this case.

[1.4, 45, 45]

Exercises 2008/2009


17. A small lamp is put in water at depth 4 cm from the surface of water

where n = 5/3 calculate the radius of the smallest circular disc of cork which when

placed on the surface of water the lamp can not be seen.

[3 cm]

18. If the critical angle of water relative to air is 48 12’ and of glass relative

to air is 41 find the critical angle between glass and water.

[61.65]

19. Knowing that absolute refractive index of glass is 1.5 and that of water is

1.32 and the velocity of light in water = 2.273x108 m/s find:

a) Relative refractive index from glass to water.

b) c from glass to air.

c) Velocity of light in glass.

[0.88, 41.81, 2x108 m/s]

20. A light ray falls at one face of a triangular glass prism so that it makes an

angle 44 with that face. Find the angle of the prism if the ray emerges with an

angle 54 and angle of deviation is 40.

[60]

21. A light ray falls normal to one side of triangular prism of equal sides, it

emerges tangent to the other side, determine the refractive index of the prism.

[1.155]

22. A ray of light falls perpendicular to one face of a glass prism of angle 45

and emerges tangent to the opposite face of the prism. Given that velocity of light

in air = 3x108 m/s. Find:

a) Refractive index of the glass prism.

b) Velocity of light in glass.

Exercises 2008/2009


[1.4, 2.1x108 m/s]

23. Calculate the smallest angle of incidence of light ray which when fall at

one face of an isosceles triangular glass prism it emerges from the other side

knowing that n of glass = and A = 75. Trace the ray if the incident angle

decreases by 5

[45]

24. Find the smallest angle of deviation of an equilateral triangle for a beam

of light falling on it if its refractive index is 1.732. What will be the angle of

deviation if the prism is immersed in a liquid of refractive index 1.224.

[60, 30]

25. Calculate the angle of a triangular glass prism of n = root 3 when a ray of

light falls on one of its faces at an angle 60 it emerges perpendicular to the

opposite face.

1 (?) 2

2 (?) 1.5

3 (?) Because the velocity of light in air or space is greater than its velocity in any

materialistic medium.

4 (?) Because in the reflected prism the reflection is 100% and does not cause to

lose any portion of the incident light.

5 (?) The waves of each color is different due to its refractive index.

6 (?) Because when a ray of light enters the tube of the optical fiber, it suffers

successive reflections (since the angle of incidence is greater than the critical

angle) till it emerges from the other end of the tube.

7 (?) Due to air density beside the earth is less than that faraway, consequently this

leads to difference in refractive index………

Exercises 2008/2009


[30]

26. A thin prism its angle = 10 the refractive index for the blue color is

1.664 & for the red color is 1.644 Calculate:

a) Average deviation.

b) Angular dispersion between the two colors.

c) The depressive power of the prism.

[6.54, 0.2, 0.03058]

27. A light ray enter perpendicular to a prism of angle 30 find the angle of

emergence if n = 1.5

[48.6]

28. Calculate the angle of the thin prism made of glass (n = 1.5) which when

put in water deviates light rays falling on it from water by an angle 1 if n of water

is 4/3.

[8]

29. Two thin prisms A, B when put with their bases are on one side angle of

deviation is 5, but when B is reversed angle of deviation is 1 find the angle of

deviation in each prism separately, also find refracting angles of the two prisms if n

of (A) is 1.5 and that of B is 1.4

[3,2,6,5]

30. A thin prism of angle 10 and of refractive index 1.5 for red and 1.53 for

blue color. Calculate:

a) The angle of deviation for

both red and blue colors.

b) The depressive angular size of

such prism.

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c) The depressive power of such

prism.

[5, 5.3, 0.3, 0.058]

31. (August 98) A ray of light falls in air on one face of a triangular glass

prism whose angle is 72 it is refracted by an angle 30 and emerges tangentially to

the other face find:

a. The critical angle between glass and air.

b. The refractive index of the prism’s material.

c. The sine of the first angle of incidence.

[42, 1.5, 0.75]

32. (August 97) A thin prism has an angle of 4, its refractive index is 1.5.

Find the angle of deviation of light passing through it.

[2]

33. (Egypt 2000) A light ray is incident with an angle 60 on one side of an

equilateral triangular prism of refractive index (root 3). Find the angle of

emergence of the light ray from the other side and its angle of deviation.

[60, 60]

34. A light ray falls on a triangular prism by an angle 60. It emerges by an

angle 30. If the refractive index of such prism 1.5. Find the refractive angle of the

prism.

[54.7]

35. Light ray falls normal to one side of a prism and emerges tangent to the

other side. If the refractive index of such prism is root 2. Find the refractive angle

of the prism.

[45]

Exercises 2008/2009


36. A thin prism of angle 10 and of refractive index 1.51 for red and 1.53 for

blue color. Calculate:

a. The angle of deviation for both red and blue colors.

b. The depressive angular size of such prism.

c. The depressive power of such prism.

[5.1, 5.3, 0.2, 0.04]

37. (August 96) The following table gives the values of sin in a medium

and the corresponding sin represents the angle of refraction of light in air:

Sin 0 0.35 0.50 0.65 0.77 0.87 0.95 0.99

Sin x 0.23 0.33 0.43 0.51 0.58 0.63 y

Plot a graphical relation between sin on the ordinate and the corresponding sin on

the abscissa. From the graph, find:

a. The value of each X and Y.

b. The absolute refractive index of the considered medium.

c. The sin of the critical angle for the considered medium.

8(?) The path of the light rays in the figure, because the ray passes without refraction,

the incident angle = zero and also the refractive angle = zero, then it falls on the side

ab and totally reflected inside the prism 90>c. The critical angle of the glass 42

as follows:

[1.5 mark]

[1 mark for the drawing]

Exercises 2008/2009


[0, 0.657, 1.5, 0.66]

38. (August 2000) The following table illustrates the relation between sine

the angle of incidence of light ray in air (sin ) and sine the angle of refraction in

glass (sin ):

Sin 0 0.15 0.3 A 0.6 0.75 0.9

Sin 0 0.1 0.2 0.3 0.4 0.5 b

Draw a graph relating (sin ) on the y-axis and (sin ) on the x-axis. From the graph,

find:

a. The values of (a) and (b).

b. The refractive index of the glass.

39. (Egypt 2001) The graph in front of you represents the relationship

between the incidence angles (1) and the

deviation angles () of light ray falling on

one face of a triangular prism. Using the

values shown in the figure calculate:

1- The emergence angle of the ray.

2- The refractive angle of the prism.

3- The refractive index of the prism material.

[48.5, 60, 1.5]

40. (August 2001) The following table shows the relation between refractive

angles of a light ray which incident on the one face of a triangle prism (1) and the

second incident angles of the same ray on the other face of the prism (2):

1 0 15 20 A 35 40 55

2 B 45 40 30 25 20 5

Exercises 2008/2009


Draw the graphical relation between (1) in the [x – axis] and (2) in the [y – axis] and

from the figure find:

a) The value of (a) and (b).

b) The refractive index of the prism material if you know that, the deviation

angle () when the prism in the minimum deviation = 37.2

[30, 60, 1.5]

Previous exams:

1. (Egypt 2003) In young's double slit experiment the separating distance between

the two slits was 0.2 mm, and the distance between the slits and the screen on

which the fringes are formed was 120 cm, if the distance between two successive

illuminated fringes is 3 mm, calculate the wavelength of the monochromatic light

in angstrom.

[30, 60, 1.5]


2. What is the length of green light wave in the water, given that its wavelength in

vacuum equals 5600A and refractive index of water 4/3

[4200A]

3. If the speed of light in air 3 x 108 m/s, and in glass 2 x 108 m/s, calculate the

refractive index (absolute) in glass.

[3/2]

4. If the refractive index of water 4/3 and of alcohol 3/2. Calculate the refractive

index from water to alcohol.

[9/8]

5. An incident ray falls on the surface of glass rectangular block of refractive index

1.5 by an incident angle equals 60, Calculate the refractive angle.

Exercises 2008/2009


[35.2]

6. An incident ray falls on the surface of water by an incident angle 60, a part of the

incident ray is reflected and other part is refracted and the reflecting and refracting

rays are perpendicular to each other. Calculate the refractive index of water.

[1.73]

7. An incident ray (in the air) falls on face of a glass rectangular block, its refractive

index it is emerged with an angle 45, calculate the angle of incidence and the

angle of refraction.

[30, 45]

8. A glass rectangular block is placed on the reflecting surface of a plane mirror and

the absolute refractive index of glass is , if an incident ray inclines on the face

of the block with an angle 30 and refracts then reflects then emerges from a point

at a distance 2 cm from the incidence point, determine the thickness of the

rectangular block.

[ ]

9. If the absolute refractive index of benzene equals , calculate the critical angle

between benzene and air.

[45]

10. An electric torch is immersed in a liquid its absolute refractive index 5/3 at a depth

equals 8 cm, calculate the radius of the smallest disc can prevent the light of this

torch to emerge in air.

[6 cm]

11. A swimming pool filled with water to its edge, the depth of water is 2 m, an

electric bulb is placed at distance equals 8 m from the edge of the pool over a

column its height 6 m, calculate the length of non apparent part form the pool

Exercises 2008/2009


bottom which the light does not reach to it, given that the refractive index of water

is 4/3.

[1.5 m]

12. In double slit experiment the distance between the midpoint of the two holes

equals 10-4 m, and the distance between the slit and the screen (which receives the

fringes) is 80 cm, calculate the distance between two successive fringes, given that

the wavelength of falling light is 5000 A.

[4 mm]

13. In double slit experiment the distance between two successive fringes is 3 mm,

and the distance between the two rectangular slits 0.0006 m, the distance between

the screen and the slits 2 m, calculate the wavelength of falling light.

[6000 A]

14. A green light falls on the double slit, its wavelength is 5500 A, the distance

between the slit and the screen is 20 cm, and the distance between the lighted

fringe and the successive dark fringe is 0.0024 cm, calculate the distance between

the two slits.

[2.3 mm]

15. A glass triangular prism, its refractive angle 60, a light ray falls on one of its sides

with an angle 45, if the refractive index of the prism is calculate:

a) Emergent angle.

b) Angle of deviation.

[45, 30]

16. A light ray falls perpendicularly on one side of a triangular prism, its angle is 30 ,

and its refractive index 1.5, calculate the angle of emergence from the other side.

[48.6]

Exercises 2008/2009


17. A ray of light falls on one side of a triangular prism, its angle is 40 and its

refractive index is 1.3, the ray emerged perpendicularly on the other side,

determine the angle of incidence.

[56.6]

18. A ray of light falls perpendicularly on one side of a glass triangular prism it

emerged as a tangent on the other side, if the refractive angle of the prism 45,

calculate the speed of light in the glass.

[2.1x108 m/s]

19. A light ray falls perpendicularly on one side of a triangular prism it emerged as a

tangent on the other side, if the refractive index of this prism is Determine the

refractive angle of this prism.

[45]

20. An equilateral triangular prism its refractive index is 1.6 determine:

a) The smallest angle of deviation of a light ray which can pass

through this prism.

b) The smallest angle of deviation when it immersed in alcohol of

refractive index 1.2

[40.20, 23.4]

21. A triangular prism its angle is 75 and its refractive index determine the smallest

incident angle of light ray on one of its sides so that it allows the ray to pass from

the other side.

[45]

22. Thin prism deviate the rays by an angle of 4 degrees and its main angle equals 8,

determine its refractive index.

[1.5]

Exercises 2008/2009


23. A thin prism its angle is 8 determine the angular size between the red and violet

color, given that the refractive index of the prism to the violet color is 1.7 and to

the red color is 1.5

[1.6]

24. A light ray falls on one face of a triangular prism with an angle equals 30, it is

emerged perpendicularly on the other face, if the refractive index of the prism

determine its angle.

[30]

25. A ray of light falls at an angle 60 on surface of water, locate the direction of

reflected and refracted rays and the angle between them given that n of water is

1.33.

[40.36, 79, 37]

Exercises 2008/2009


Model Answer

Exercises 2008/2009

Documents

eu1c3 By Adel Khamis