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.