LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
B.Sc. DEGREE EXAMINATION – PHYSICS
FIFTH SEMESTER – APRIL 2012
PH 5509/PH 5506/PH 3500 – OPTICS
Date : 30-04-2012 Dept. No. Max. : 100 Marks
Time : 9:00 – 12:00
PART – A
Answer ALL questions: (10 x 2 = 20 marks)
- What are nodal planes? When do nodal points coincide with the principal points?
- What is Abbe’s sine condition? Where is it applied?
- What is the principle behind the appearance of beautiful colors produced by the thin film of soap bubble?
- What is fringe width?
- What is a zone plate? In which aspect is it different from a convex lens?
- What is grating element? Write one use of grating
- If the refractive index of glass is 1.5, what is the angle of polarization?
- Which type of crystals exhibit double refraction? why? Give an example
- Write down any four characteristics of laser beam?
- Differentiate between spontaneous emission and stimulated emission
PART – B
Answer any FOUR questions: [4 x 7.5 = 30 marks]
- Compare and contrast Huygen’s eyepiece and Ramsden’s eye piece.
- The width of the fringes obtained on a screen kept at a distance 80 cm from a biprism is 9.424 x 10 – 8 cm. What is the distance between the two coherent sources if the wave length of sodium light used is 5890 A0?
- What is Rayleigh’s criterion for the resolution of spectral lines? Obtain an expression for the resolving power of a telescope.
- How would you produce, detect [a] plane polarized and [b] circularly polarized light?
- What is non linear optics? Explain how second harmonics are generated?
PART – C
Answer any FOUR questions: [4 x 12.5 = 50 marks]
- [a] Define the term dispersive power. [b] Explain how two narrow angled prisms of different dispersive powers may be combined to produce [i] dispersion without deviation and [ii] deviation without dispersion.
- With the neat diagram, describe the construction and working of a Michelson’s interferometer and discuss its applications.
- What is Fraunhofer diffraction? Discuss the Fraunhofer diffraction pattern due to a single slit and hence explain how the wavelength of light is determined using it.
- What is optical activity? Outline the principle and working of a half shade polarimeter and explain how the specific rotation of glucose is determined using it.
- With the neat diagram, explain the construction, principle of working , energy level diagram and applications of He – Ne laser.
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