Question

A heat flux of 4000 J/s is to be passed through a copper rod of length 10 cm and area of cross-section 100 cm². The thermal conductivity of copper is 400 W/m^0C. The two ends of this rod must be kept at a temperature difference of

• A. 1 ^0C
• B. 10 ^0C
• C. 100 ^0C
• D. 1000 ^0C

Answer 1

Answer: (C)

100 ^0C

Answer 2

From $\frac{dQ}{dt} = \frac{KA\Delta\theta}{l}$ ⇒ $\Delta\theta = \frac{l}{K \times A} \times \frac{dQ}{dt}$

$= \frac{0.1}{400 \times (100 \times 10^{- 4})} \times 4000$= 100^oC