Question

Two metal rods, rod-1 and rod-2 of equal length are welded together end to end.Under steady state conditions, when the free end of the end of the rod-1 is kept at ${100}^{0}C$ and the free end of the rod -2 is kept at $0^{0}C$ , the temperature at the welded junction is approximately.

[Thermal conductivity of rod-1 = $92J{s}^{-1}{m}^{-1}{K}^{-1}$, and rod-2 =$16J{s}^{-1}{m}^{-1}{K}^{-1}$]

• A. ${85}^{0}C$
• B. ${50}^{0}C$
• C. ${75}^{0}C$
• D. ${95}^{0}C$

Answer 1

The correct option is A ${85}^{0}C$

Heat Current = $i=\frac{KA\Delta T}{L}$

$K_1(T_1-T)=K_2(T-T_2)$

$92(100-T)=16(T-0)$

$⟹T={85}^{o}C$