Question

The temperature of the two outer surfaces of a composite slab, consisting of two materials having coefficients of thermal conductivity K and 2K and thickness x and 4x, respectively are T₂ and T₁ (T₂ > T₁ ). The rate of heat transfer through the slab, in a steady state is (A(T₂ - T₁)K/x)f , with f equal to

(a) 1 

(b) 1/2

(c) 2/3 

(d) 1/3.

Answer 1

Correct Option (d) 1/3

Explanation:

Let the temperature of common interface be T°C. Rate of heat flow