PREVIOUS EXAMINATION QUESTIONS IN FIBER OPTICS

1.      Explain the principle of an optical fiber.

2.      Describe the fiber construction.

3.      Describe the function of single mode step index optical fiber along with its refractive index profile.

4.      Explain why step index optical fiber is of reflective type.

5.      Explain why graded index optical fiber is of refractive type.

6.      Explain the advantages of graded index optical fiber when compared to step index optical fiber.

7.      Describe the function of multi mode step index optical fiber along with its refractive index profile.

8.      Distinguish between single mode and multi mode step index optical fibers.

9.      What is total internal reflection? Discuss its importance in optical fiber.

10.  Describe the construction of a typical optical fiber along with the dimensions of the various parts.

11.  What is acceptance angle of an optical fiber and derive an expression for it.

12.  A fiber has a core refractive index of 1.44 and cladding refractive index of 1.4. Find its acceptance angle.

13.  What is the Numerical aperture of an optical fiber and derive an expression for it.

14.  A fiber has a core refractive index of 1.55 and cladding refractive index of 1.50.Find its Numerical aperture.

15.  Describe briefly the different types of optical fibers with neat diagrams.

16.  Calculate the refractive indices of core and cladding of an optical fiber with a numerical aperture of 0.33 and their fractional change of refractive indices being 0.02.

17.  Discuss the minimization of modal dispersion in the graded index optical fiber.

18.  An optical fiber has a numerical aperture of 0.20 and cladding refractive index of 1.59.Determine the refractive index of core and the acceptance angle for the fiber in water which has a refractive index of 1.33.

19.  What are the conditions to produce total internal reflection in optical fiber.

20.  Describe the structure of different types of optical fibers with ray paths.

21.  Explain the role of optical fibers in medicine and industry.

22.  Define acceptance angle and numerical aperture. Obtain the expression for the numerical aperture of an optical fiber.

23.  Calculate the acceptance angle and numerical aperture for an optical fiber with core and cladding refractive indices being 1.48 and 1.45 respectively.

24.  What is the principle of an optical fiber communication? Explain.

25.  Explain the advantages of optical fiber communication system.

26.  The numerical aperture of an optical fiber is0.39. If the differences in the refractive indices of the material of its core and the cladding are 0.05, calculate the refractive index of material of the core.

27.  Calculate the angle of acceptance of a given optical fiber, if the refractive indices of the core and cladding are 1.563 and 1.498 respectively.

28.  If the numerical aperture of a fiber is 0.245 with a core refractive index 1.51, calculate the refractive index of cladding as well as acceptance angle.

29.  Calculate the refractive indices of core and cladding of an optical fiber with a numerical aperture of 0.33 and their fractional difference of refractive indices being 0.02.

PREVIOUS EXAMINATION QUESTIONS IN NANO TECHNOLOGY

1. Write a detailed note on Nanomaterials.

2. Explain why Nanomaterials exhibit different properties.

3. Explain the Vibrational properties exhibited by Carbon Nanotubes.

4. Explain the basic factors of Carbon Nanotubes on which its Vibrational properties depend.

5. How the Physical and chemical properties of Nanomaterials vary with their size.

6. Write the important applications of Nanomaterials.

7. Mention the important applications of Carbon Nanotubes in Computer field.

8. Explain the usage of Carbon Nanotubes as fuel cells in batteries.

9. Explain the sensor and catalyst applications of Carbon Nanotubes.

10. Mention the important applications of Carbon Nanotubes in Material technology.

11. Mention the important applications of Carbon Nanotubes in Information technology.

12. Mention the important applications of   in Biomedical fields.

13. Mention the importance of Carbon Nanotubes in Energy storage applications.

14. Mention the important applications of Nanomaterials in medicine.

15. What are Nanomaterials? How they are classified.

16. Describe the principles of Nanomaterials.

17. What are Carbon Nanotubes? What are their properties?

18. What are the important applications of Nano particles?

19. Write a short note about Nano.

20. Write a short note of Nanomaterials.

21. Write a detailed note on Nanoscience.

22. How are Nanomaterials produced?

23. Explain the synthesis of Nano materials from sol-gel and CVD techniques.

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         

             PREVIOUS EXAMINATION QUESTIONS

                    IN

           PRINCIPLES OF QUANTUM MECHANICS                                               

1.      What are matter waves? Explain their properties. Obtain the expression for the wavelength of the matter waves.

2.      Calculate the wavelength associated with an electron raised to 1600V.

3.      Explain the concept of matter waves. Derive the expression for de-Broglie wavelength.

4.      Explain the consequences of uncertainty principle.

5.      Explain the de-Broglie hypothesis.

6.      State and explain uncertainty principle. Using uncertainty principle, explain the absence of electrons in the nucleus.

7.      Show that the energies of a particle in a potential box are quantized.

8.      Explain the Fermi-Dirac distribution function of electrons. Explain the effect of temperature on the distribution.

9.      Write notes on source of electrical resistance.

10.  Derive time independent schrodinger wave equation for a free particle.

11.  Explain the physical significance of a wave function.

12.  Explain the origin of energy bands in solids. On the basis of band theory explain how the crystalline solids are classified into metals, semiconductors and insulators.

13.  Show that the wavelength of an electron accelerated by a potential difference ‘V’ volts, is λ=1.227/√V m for non-relativistic case.

14.  Explain the differences between matter waves and electromagnetic waves.

15.  An electron is bound in a one-dimensional infinite well of width 1×10^-10m.Find the energy values in the ground state and first two excited states.

16.  Explain Kronig-Penny model for a free electron.

                                                                                                          

 PREVIOUS  EXAMINATION  QUESTIONS

                         IN OPTICS

1. Distinguish between polarized and unpolarised lights.

2. What is meant by Double refraction and discuss the construction and working principle of Nicol Prism.

3. Calculate the thickness of the half wave plate  of quartz for a wavelength 500nm,if µ_e =1.553 and µ_o =1.544.

4. Obtain the condition for primary maxima in Fraunhoffer diffraction due to a single slit experiment.

5. Differentiate between interference and diffraction intensity patterns. How do you differentiate the Fresnel diffraction and Fraunhoffer diffraction?

6. How many orders will be visible , if the wavelength of the light is 5000 A^O.Given that the number of lines per centimeter on the grating is 6655.

7. Differentiate between interference and diffraction.

8. Give the theory of  Fraunhoffer diffraction due to a double slit and compare the results with that due to single slit.

9. What are the types of diffraction and give the differences between them.

10. Obtain the condition for primary maxima in Fraunhoffer diffraction due to a single slit and derive an expression for width of the central maxima.

11. Explain what is meant by diffraction of light. How diffraction is different from interference?

12. Discuss Fraunhoffer single slit diffraction. Draw intensity distribution curves and give conditions for bright and dark fringes in single slit diffraction pattern.

13. What are coherent sources? Why any two independent sources of light cannot produce interference fringes?

14. Describe the interference pattern obtained due to superposition of coherent sources.

15.  What is meant by diffraction of light?

16. How do you obtain circular rings in Newton’s rings experiment? Determine the refractive index of transparent liquid by using Newton’s rings experiment.

17. In a Newton’s rings experiment, the diameter of 10^th dark ring changes from 1.40cm to1.27cm when a liquid is introduced between the lens and the plate. Calculate the refractive index of the liquid.

18.  Explain the principle of super position of waves.

19. With ray diagram discuss the theory of thin films and the condition for constructive and destructive interference in the case of reflected system.

20. A parallel beam of light λ=5800A^O incident on a glass plate µ=1.5 such that angle of refraction in to plate is 60^o.Calculate the smallest thickness of the plate which will make it appear dark by reflection.

21. Give the theory of colors in thin films with a ray diagram for a reflected system.

22. Thin film of thickness 0.2mm is illuminated by light of wavelength 620nm.If the 3^rd dark band was observed at the refracting angle of 5^o35’. Calculate the refractive index of the film.

23. What is meant by polarization of light?

24. Describe an experiment that shows light is not propagated as longitudinal waves.

25. What is plane of vibration?

26. Give the theory of Fraunhoffer diffraction due to n slits.

27. Write a short note on Diffraction grating and Diffraction spectrum.