Heat And Thermodynamics

Two slabs are of the thicknesses \(d_1\) and \(d_2\). Their thermal conductivities are \(K_1\) and \(K_2\), respectively. They are in series. The free ends of the combination of these two slabs are kept at temperatures \(\theta_1\) and \(\theta_2\). Assume \(\theta_1 > \theta_2\). The temperature \(\theta\) of their common junction is