A wall has two layers A and B , each made of a different material. Both layers have same thickness.

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10-2.Transmission of Heat

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A wall has two layers $A$ and $B$ , each made of a different material. Both the layers have the same thickness. The thermal conductivity of the material of $A$ is twice that of $B$ . Under thermal equilibrium, the temperature difference across the wall is $36\,^oC$. The temperature difference across the layer $A$ is ......... $^oC$

$6$

$12$

$18$

$24$

Solution

$\frac{\mathrm{K}_{\mathrm{A}} \mathrm{A} \cdot\left(\Delta \mathrm{T}_{\mathrm{A}}\right)}{\ell}=\frac{\mathrm{K}_{\mathrm{B}} \cdot \mathrm{A} \cdot\left(\Delta \mathrm{T}_{\mathrm{B}}\right)}{\ell}$

$\because \mathrm{K}_{\mathrm{A}}=2 \mathrm{K}_{\mathrm{B}}$

$\therefore \Delta \mathrm{T}_{\mathrm{B}}=2 \Delta \mathrm{T}_{\mathrm{A}}$

$\Delta \mathrm{T}_{\mathrm{A}}+\Delta \mathrm{T}_{\mathrm{B}}=36$

$3 \Delta T_{A}=36$

$\Delta \mathrm{T}_{\mathrm{A}}=12^{\circ} \mathrm{C}$

Standard 11

Physics

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Solution

Similar Questions

In a room where the temperature is ${30^o}C$, a body cools from ${61^o}C$ to ${59^o}C$ in $4$ minutes. The time (in min.) taken by the body to cool from ${51^0}C$ to ${49^0}C$ will be ……. $\min$

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