Question

Consider a compound slab consisting of two different materials having equal thickness and thermal conductivities K and 2K respectively. The equivalent thermal conductivity of the slab is

• A. $\sqrt{2}K$
• B. $2K$
• C. $\frac{4}{3}K$
• D. $\frac{2}{3}K$

Answer 1

The correct option is C $\frac{4}{3}K$

$K=\frac{2K_1{K}_2}{K_1+K_2}=\frac{2.K.2K}{K+2K}=\frac{4}{3}K$.