#### Set - 1

#### I - B.Tech. Supplementary Examinations, Aug/Sep – 2008 (E.E.E, E.C.E, C.S.C, C.S.I.T, E.I.E, B.M.E, E.Con.E, C.S.S.E, E.Tele & E.Com.E)

**Time: 3 hours** |
**Max. Marks: 80** |

#### Note: Answer any FIVE questions

#### All questions carry equal marks

1a. Define coordination number and packing factor of a crystal.

b. Describe BCC crystal structure, with a suitable example.

c. Obtain an expression for the packing factor of FCC structure. (4 + 6 + 6)

2a. Derive 3-dimensional, time independent Schrodinger wave equation for an electron.

b. What is the physical significance of wave function?

c. Deduce the expression for energy of an electron confined to a potential box of width ‘x’. (6 + 4 + 6)

3a. Discuss with suitable mathematical expressions, the Kronig-Penney ...