Assignment Questions for Mech-C

1. Define density of states
2.What is relaxation time or mean free time ?

3. For copper the mean free time is 10^-14 sec. The free electron density is 2 x 10²⁸/m³. Calculate its    electrical conductivity.

4.An electron  inside a metal is acted upon by an external electric field and explain about its velocity and its motion.

5.What are the postulates of classical free electron theory?

6.What are the drawbacks of classical free electron theory?

7.The molecules are in random motion inside a container. Bring out the kinetic energy of the molecules at any given temperature. 

8.If the difference in the energy above the Fermi energy is kBT, then evaluate Fermi function at 300K.

9.The electrical resistivity of copper is  1.69 x 10⁸ Ωm. Thermal conductivity is 390 W/m/k. Evaluate its Lorentz number.

10. Define Fermi energy level at any temperature.