Basic Concept of Thermal Conductivity.
The given figure shows a composite slab of three different materials, a, b, and c with identical thickness and with thermal conductivity \( k_b > k_a > k_c \). The transfer of energy through them as heat is non-zero and steady. The temperature difference across material a, b and c are \(\Delta T_1\), \(\Delta T_2\) and \(\Delta T_3\) respectively. Then :