Question

There are three slabs placed side by side as shown in the figure. Heat generation takes place in slab (2) only and thermal of conductivity of slab (1) is greater than that of slab (3).
Which one of the following profiles of heat flux is correct? (Consider steady, 1 - D heat conduction and same environmental conditions for both slab (2) and slab (3)).

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

Heat flux (q) = -k$\frac{\text{dT}}{\text{dx}}$

$\frac{\text{dT}}{\text{dx}}=0$, where the temperature is maximum

(due to heat generation)
$\therefore$ q = 0

whatever the heat generates in slab(2), the same heat will transfer through slab (1) and slab(3).

Slab (1) conducts more heat because its thermal conductivity is greater than that of slab(3).

$\therefore q_1>q_3$

where, $q_1=$ heat flux in slab (1), and
$q_3=$ heat flux in slab (2)