Two rods of the same length but different thermal conductivities K1 and K2 are joined end to end (in series) are arranged. The ends are maintained at temperatures of 100∘C and 70∘C. The temperature T at the junction point?
Given-
To find- T
Solution- In steady-state heat conduction, the rate of heat flow (Q) through both rods must be equal = $$
\frac{K_{1}A(100−T)} {L}= \frac{K_{2}A(T−70)} {L}
$$
As A and L are the same. So, $$
{K_{1}(100−T)}= {K_{2}(T−70)}
$$ $$
100K_{1}+ 70 K_{2}= T{(K_{1}+ K_{2})}
$$ $$
T= \frac {100K_{1}+ 70 K_{2}}{(K_{1}+ K_{2})}
$$