Question

The thermal conductivity of a material in CGS system is 0.4. In steady state, the rate of flow of heat 10 cal/sec-cm², then the thermal gradient will be

• A. $10{^\circ}C/cm$
• B. $12{^\circ}C/cm$
• C. $25{^\circ}C/cm$
• D. $20{^\circ}C/cm$

Answer 1

Answer: (C)

$25{^\circ}C/cm$

Answer 2

$\frac{\Delta Q}{\Delta t} = \frac{KA\Delta\theta}{\Delta x}$⇒ Thermal gradient$\frac{\Delta\theta}{\Delta x}$

$= \frac{(\Delta Q/\Delta t)}{K} = \frac{10}{0.4} = 25{^\circ}C/cm$