Salman bin Abdel-Aziz University
104 Phys
Faculty of Science in Al-Afaj
Electricity and Magnetism + Optics
Department of Physics
Revision
OPTICS
CHAPTE R 23 – Electric fields
‫ ولكنها مجرد نماذج ألسئلة االختبارات للتدريب عليها‬،‫هذه المراجعة ليست ملخص للمادة وال يكتفى بها‬
This revision is not a compendium for the subject and not enough, it is
only a model for the exam's questions for training.
You may need to physical constants of the following:
1) Speed of light
[c = 3 × 108 m/s]
2) Planck’s constant
[h = 6.63 × 1034 J.s]
3) Index of refraction
(Q1) Which statement is true (√) and which is false (×) of the following:
(Q1) Correct the mistakes in the following sentences if found:
) Newton is the chief architect of the particle theory of light.
) Newton held that particles were emitted from a light source and that these particles stimulated the sense
of sight upon entering the eye.
) Newton was able to explain reflection and refraction of light.
) Huygens set up the wave theory of light.
) Huygens was able to explain reflection and refraction of light.
) Huygens showed that a wave theory of light could also explain reflection and refraction.
) The wave theory of light was proposed that light might be some sort of wave motion.
) Maxwell asserted that light was a form of high-frequency electromagnetic wave.
) Hertz provided experimental confirmation of Maxwell’s (electromagnetic wave) theory by producing
and detecting electromagnetic waves.
) The wave model and the classical theory of electricity and magnetism were able to explain most known
properties of light.
) The wave model and the classical theory of electricity and magnetism could not explain some
subsequent experiments such as the photoelectric effect.
) The photoelectric effect was discovered by Hertz.
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) Light exhibits the characteristics of a wave in some situations and the characteristics of a particle in
other situations.
) Hertz found that when light strikes a metal surface, electrons are sometimes ejected from the surface.
) According to Einstein’s theory, the energy of a photon is proportional to the frequency of the
electromagnetic wave
) Sometimes light acts like a wave, and at other times it acts like a particle.
) Fizeau succeeded to measure the accurate value of speed of light.
) Fizeau succeeded to measure the speed of light more accurately than Roemer.
) Einstein sets up the wave theory of light.
) Reflection is one of the properties of the visible light and not of the rest of the electromagnetic waves.
) Total internal reflection occurs only when light is directed from a medium of a given index of refraction
toward a medium of higher index of refraction.
) A ray of single-wavelength light incident on the prism from the left emerges refracted from its original
direction of travel by an angle , called the angle of deviation.
) Optical fiber is interesting application of total internal reflection
) Optical fiber is based on the total internal reflection phenomena.
) The idea of the optical fiber is based on the phenomenon of total internal reflection.
) The path of a light ray through a refracting surface is reversible.
) The speed of light in any material is less than its speed in vacuum.
) Light travels at its maximum speed in vacuum.
) The index of refraction n of a medium is the ratio between speed of light in vacuum c and speed of light
in medium v.
) The index of refraction is a dimensionless.
) The index of refraction is a dimensionless number greater than unity
) As light travels from one medium to another, its frequency does not change but its wavelength does.
) The index of refraction varies with the wavelength of the light passing through a material.
) Dispersion of light occurs due to the variation of the index of refraction varies with the wavelength
of the light passing through a material.
(Q2) Choose the correct answer:
) The …………. theory of light was proposed that light might be some sort of wave motion.
a) wave
b) particle
c) quantum
) If a photon has energy of 6.63 × 1031 J, it's frequency will be
a) 1000 Hz
b) 100 Hz
c) 10 Hz
d) ether
d) 1 Hz
) In the movies, you sometimes see an actor looking in a mirror and you can see his face in the mirror.
During the filming of this scene, what does the actor see in the mirror?
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a) his face
b) the director’s face
d) the movie camera
e) impossible to determine
) Light passes from a material with index of refraction 1.3 into one with index of refraction 1.2.
Compared to the incident ray, the refracted ray
a) bends toward the normal
b) is undeflected
c) bends away from the normal
(Q3) Complete the missed words:
) Reflection of light from a smooth surface is called …………………...
) …………… is the main source of light and heat.
) A ray of single-wavelength light incident on the prism from the left emerges refracted from its original
direction of travel by an angle , called …………………………….
* Choose the missed words from the following:
(capacitance – directly – inversely – angle of deviation – defuse – specular – Sun)
(Q4) What is the scientific reason of the following:
1) The index of refraction is always greater than unity.
This is because the speed of light in medium v is always less than the speed of light in vacuum c.
2) The refraction phenomena of light (when the light passes from medium to another medium with
different density).
Because the speed of light differs from medium to another medium.
3) Occurance of the dispersion of light when it passes through a prism.
It is due to the difference of the refractive index for every coulor of the visible light.
(Q5) State the following laws:
1) The law of reflection
2) Snell's law
(Q6) Essay questions:
) Discuss how to measure the index of refraction using a Prism
(Q7) Solve the following problems
) A light ray of wavelength 589 nm traveling through air is incident on a smooth, flat slab of crown glass
at an angle of 30° to the normal. Find the angle of refraction and the angle of deviation.
) If a light beam has an energy with 1.326×10-30 J. Calculate the frequency of this beam. Plank's constant
equals 6.63×10-34 J.s.
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) A laser beam strikes a vertical surface at angle of 30o, the reflected beam can be seen as a spot on
horizontal surface. The spot is 50 cm away from the point of incidence on the vertical surface. How far
the horizontal distance from the spot to the reflected surface.
) Find the critical angle for an air–water boundary. (The index of refraction of water is 1.33.)
(Q8) Write the terms in the following diagram:
3
5
1
2 4
8
9
6
10
7
(8) Air
(9) The air –glass interface
(10) Glass
(Q9) Define the following terms
1) Diffusive reflection
2) Specular reflection
3) Refractive index
(Q10) Mention the measurement units of the following terms:
1) Frequency
3) Planck’s constant
10) Wavelength of light
12) speed of sound
13) Speed of electromagnetic waves
4) Refractive index
7) Light velocity
14) Energy of light
Q11): Mention the measurement units of the following terms:
Quantity Frequency
Planck’s
constant
Energy
of light
Planck’s
constant
Speed
of light
Unit
(Q12) Give the scientific terms of the following definitions:
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wavelength
speed of index of
sound refraction
) The angle between the refracted ray and the normal line of the incident point.
) The angle of incidence when the refracted light ray moves parallel to the boundary (surface) so that the
angle of refraction angle is 90°.
) The ratio between the velocity of light in air and the velocity of light in a medium.
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