Consider a compound slab consisting of two different materials having equal thicknesses and thermal conductivities K and 2K , respectively. The equivalent thermal conductivity of the slab is (a) 2/3 K (b) √2K (c) 3K (d) 2/3 K
The slabs are in series. Total resistance R = R1+R2 = l/Ak = l/Ak + l/A2K = l/ Keff= l/K + l/2K = 3/2K Keff = 2K/ 3
