JEE Mains Model Paper 12

Let θ be the temperature at point C at a distance x from end A of the bar whose ends arekept at temperatures θ1 and θ2 with θ1>θ2 . L – length of the bar.
In steady state, the rate of flow of heat from A to C = rate of heat flow from C to B
i.e.,

KA(θ1−θ)

x

=

KA(θ−θ2)

L−x

⇒ θ = θ1 - (

θ1−θ2

L

) x
Thus, the graph of θ versus x is a straight line with a positive intercept and negative slope.