JNTU Engineering Physics Exam Papers May June 2008
1. (a) Explain the concept of coherence.
(b) Discuss why two independent sources of light of the same wavelength cannot produce interference fringes.
(c) What are the necessary conditions for obtaining interference fringes.
2. (a) Explain the factors like reverberation, reverberation time, loudness and echo are affecting the architectural acoustics.
(b) How the above mentioned difficulties are overcome.
3. (a) What are ferromagnetic domains?
(b) Discuss Weiss theory of ferromagnetism.
(c) What are its merits and demerits?
4. (a) Define packing factor of a unit cell.
(b) Show that the packing factor for simple cubic, body centered and face centered lattices are 52%, 68% and 74% respectively.
(c) Iron has BCC structure with atomic weight 55.85 and density 7860 kg/m3. Find the lattice constant.
5. (a) Describe how population inversion is very important in laser.
(b) Explain the modes of vibrations of CO2 molecule. Describe the construction and working of CO2 laser with necessary diagram.
(c) Distinguish between homojunction and heterojunction semiconductor laser.
6. (a) What are the points are important to mention single mode fiber?
(b) Explain with a block diagram, the basic instrumentation technique adopted to explain the communication system.
(c) A fiber has a core refractive index of 1.44 and cladding refractive index of 1.4. Find its numerical aperture and acceptance angle.
7. (a) Define thermal capacity.
(b) Derive the unit of thermal conductivity.
(c) Derive and discuss one dimensional lattice vibrations in solids.
8. (a) What is the principle behind the TEM?
(b) Explain the transmission electron microscopy.
(c) Give the advantages of TEM.