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Salman bin Abdulaziz UniversityCollege of Science and Humanitarian Studies
Physics Department / 2014
Final Exam
1434/1435هـ / / التوقيع / المصححون
د/ محمد عبده المرسي
د/ عباس محمد إمام
Second semester
Optics II
(2250 phys)
Time : Two hours
Question / One / Two / Three / Four / Five / TotalMarks
15 / 15 / 15 / 15 / 15 / 60
وضح اجابتك بالرسم قدر المستطاع ....Explainyour answerby drawingas possible as you can
إسم الطالب: / الرقم الجامعىرقم المجموعة
Answer the following question
Question one
(A)Choose the correct answer
( 8 marks )
(1)The total energy of a vibrating particle is given by(2)Two sources are said to be monochromatic if they emit light waves of thesame
Length / Position / Wavelength
(3)The phase difference is is given by
(4)The condition of dark fringe at Young's Experiment is
(5)The condition of dark fringe at Llod's Experiment is
(6)According to the fringe produced by a wedge shaped thin film, the fringe wedge is given by
(7)The condition of dark fringe at Newton's rings is
(8)The angular velocity is given by
(B)Write the physical definition of (1) wavelength, (2) The refractive index, (3) the frequency , (4) the coherentsources.
(1) Wavelength( 1 mark )
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(2) The refractive index ( 2 marks )
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(3) The frequency( 2 marks )
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(4) the coherentsources( 2 marks )
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Answer only three questions from the following questions
Question two
(A)determine the thickness of a thin sheet of transparent material using Fresnel's biprism.
( 8 marks )
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(B) When a thin piece of glass 3.4 x10-4 cm thick is placed in the path of one of the interfering beams in a biprism arrangement, it is found that the central bright fringe shifts through a distance equal to the width of four fringes. Find the refractive index of the piece of glass. Wavelength of light used is 5.46 x 10-5 .cm. ( 7marks )
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Question three
(A) Discuss Fraunhofer diffraction at a narrow. Draw a curve indicating distribution of light in the diffraction pattern. Is there any fundamental difference between interference and diffraction?
( 8 marks )
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(B)Describe the construction of Mack-Zender interferometer and explain its working. ( 7 marks )
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Question Four
(A)Prove that , the optical path difference (X) of interference in thin films( at reflection) is given by . ( 8 marks )
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(B) A parallel beam of light ( =5890 x10 -8 cm) is incident on a thin glass plate( µ = 1.5) such that the angle of refractioninto the plate is60°. Calculate the smallest thickness of the glass plate which will appear dark by reflection
( 7 marks )
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Question Five
(A)Show that the total energy of a vibrating particle at any instant is directly proportional to the square of the amplitude and the square of frequency. ( 7 marks )
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(B) Using the analytical method to calculate the composition of the following two simple harmonic motions:
( 8 marks )
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With my best wishes
Dr / Mohamed El-Morsy