Question

The thickness of a metallic plate is 0.4 cm. The temperature between its two surfaces is $20^{o}C$. The quantity of heat flowing per second is 50 calories from $5cm^{2}$ area. In CGS system, the coefficient of thermal conductivity will be

• A. 0.4
• B. 0.6
• C. 0.2
• D. 0.5

Answer 1

Answer: (C)

0.2

Answer 2

$\frac{Q}{t} = \frac{KA(\Delta\theta)}{l}$⇒ $50 = \frac{5 \times 20\mspace{6mu} K}{0.4} \Rightarrow K = \frac{1}{5} = 0.2$