Transference of heat conduction mode and conductivity

conduction of heat and Lees disc method of determining conductivity

1. HEAT

2. Radiation Conduction Convection

3. θ 1 θ 2 x A k Thermal conductivity.

4. Thermal conductivity Temperature gradient the temperature θ , decreases as the distance, x increases

5. The ratio of the thermal conductivity of the material and the electrical conductivity of the material is directly proportional to absolute temperature. Boltzmann constant Wiedemann –Franz law

6. Determination of k of a bad conductor by Lee’s Disc method

7. θ 1 θ 2 Temperatures recorded in the thermometers will show a rise and finally will be steady at θ 1and θ 2. wait for 10 minutes T 1 T 2 Rate of cooling at θ 2

8. Rate of cooling at θ 2 Remove B heat C directly by the steam chamber till its temperature is about θ 2 + 10° Disc C alone is suspended and allowed to cool Start recording temperature at intervals of 30 seconds. Continue till the temperature falls by 10°C below θ 2 . Plot temperature-time graph.

9. Time (s) Temperature( c) θ 2 A B C

10. Actual rate of cooling=