The temperature drop through each layer of a | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) For a steady-state heat flow through a series combination of layers,the rate of heat flow $\frac{dQ}{dt}$ is constant through both layers.The rate

Vedclass · Accepted Answer

$k_1 > k_2$

Vedclass · Answer

(A) For a steady-state heat flow through a series combination of layers,the rate of heat flow $\frac{dQ}{dt}$ is constant through both layers.The rate of heat flow is given by $\frac{dQ}{dt} = k A \frac{\Delta T}{\Delta x}$,where $k$ is the thermal conductivity,$A$ is the cross-sectional area,and $\frac{\Delta T}{\Delta x}$ is the temperature gradient (slope of the $T-x$ graph).Since $\frac{dQ}{dt}$ and $A$ are constant,we have $\frac{\Delta T}{\Delta x} \propto \frac{1}{k}$.From the graph,the slope of the temperature profile in layer $(1)$ is less than the slope in layer $(2)$,i.e.,$|\frac{\Delta T}{\Delta x}|_1 Since the slope is inversely proportional to $k$,a smaller slope implies a larger thermal conductivity.Therefore,$k_1 > k_2$.

The temperature drop through each layer of a two-layer furnace wall is shown in the figure. Assume that the external temperatures $T_1$ and $T_3$ are maintained constant and $T_1 > T_3$. If the thicknesses of the layers $x_1$ and $x_2$ are the same,which of the following statements is correct?

Similar Questions

If two metallic plates of equal thicknesses and thermal conductivities $K_1$ and $K_2$ are put together face to face and a common plate is constructed,then the equivalent thermal conductivity of this plate will be

If the radius and length of a copper rod are both doubled,the rate of flow of heat along the rod increases ....... times.

In which case does the thermal conductivity increase from left to right?

Vedclass Test Series

Exam Paper Generator

Online Exam Module