Jawaharlal Nehru Technological University, Hyderabad B.Tech Computer Science and Engineering 1st B.tech Regular Examinations (R09) physics Question paper

Code No:09A1bs02 Set No.1

1.a)Explain the principle behind the functioning of an optical fibre.
b)Derive an expression for numerical aperture of an optical fibre.
c)Write three applications of optical fibres.

2.a)Distinguish between intrinsic and extrinsic semiconductors.
b)Derive an expression for density of holes in valence band of an intrinsic semiconductor.

3.a)What is bonding in solids?write the list of different types of bonding in solids.
b)Describe with suitable examples the information of ionic and covalent bonds in solids.
c)What is cohesive energy of a molecule?Explain.

4.a)What is Bloch theorem?Explain.
b)Write the conclusions given by Kronig-Penny model.
c)For an electron under motion n a periodic potential,plot the curve between the effective mass of the electron and wave number,and explain.

5.a)Describe any three process by which nano materials are fabricated.
b)Describe the important applications of nanotechnology.

6.a)Define magnetic moment.What is bohr magneton?Explain.
b)What are the characteristics of diamagnetic,Paramagnetic,ferromagnetic substances?Explain their behavior with the help of examples.
c)If a magnetic field of strength 300amp/metre produces a magnetization of 400A/m in ferromagnetic material,find the relative permeability of the material.

7.a)Explain the concept of dual nature of light.
b)Describe the experimental verification of matter waves using Davisson-Germer experiment.
c)Calculate the wavelength of matter wave associated with a neutron whose K.E is 1.5times the rest mass of electron.
(Given that mass of neutron=((1.676)(10pow(-27)))Kg,Mass of electron=9.1(10pow(-31))Kg,Planck's constant=6.62(10pow(-34))J-sec,Velocity of light=3(10pow(8))m/s).

8.a)Write notes on Bragg's law.
b)Describe Bragg's X-Ray spectrometer method in the determination crystal structure.
c)Calculate the glancing angle of (1 1 1) plane of the cubic crystal having axial length 0.19nm corresponding to the second order diffraction maximum for the X-Rays of wavelength 0.058nm.