Code No: R05010201 Set No. 1
I B.Tech Semester Supplimentary Examinations, June 2009
APPLIED PHYSICS
( Common to Electrical & Electronic Engineering, Electronics &
Communication Engineering, Computer Science & Engineering, Electronics
& Instrumentation Engineering, Bio-Medical Engineering, Information
Technology, Electronics & Control Engineering, Computer Science &
Systems Engineering, Electronics & Telematics, Electronics & Computer
Engineering and Instrumentation & Control Engineering)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆⋆⋆⋆⋆
1. (a) Explain the terms [6]
i. basis
ii. space lattice and
iii. unit cell.
(b) Describe the seven crystal systems with diagrams. [10]
2. (a) State and explain Bragg’s law. [6]
(b) Describe with suitable diagram, the powder method for determination of crys-
tal structure. [6]
(c) A beam of X-rays of wavelength 0.071 nm is diffracted by (110) plane of rock
salt with lattice constant of 0.28 nm. Find the glancing angle for the second
order diffraction. [4]
3. (a) Derive time independent Schrodinger’s wave equation for a free particle. [8]
(b) Explain the physical significance of wave function. [4]
(c) 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. [4]
4. (a) Explain the origin of energy bands in solids.
[6]
(b) Assuming the electron - lattice interaction to be responsible for scattering of
conduction electrons in a metal, obtain an expression for conductivity in terms
of relaxation time and explain any three draw backs of classical theory of free
electrons. [6]
(c) Find the temperature at which there is 1% probability of a state with an
energy 0.5 eV above Fermi energy. [4]
5. (a) Explain how the magnetic materials are classified from the atomic point of
view. [6]
(b) What are the differences between hard and soft magnetic materials. [6]
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