Two rods of equal length and area of cross-section are kept parallel and lagged between temperature 20$℃$ and 80$℃$. The ratio of the effective thermal conductivity to that of the first rod is $\left\lbrack the\ ratio\ \left( \frac{K_{1}}{K_{2}} \right) = \frac{3}{4} \right\rbrack$

Question

Dr. Abubacker · Accepted Answer

(b) For parallel combination of two rods of equal length and equal area of cross-section.
$K = \ \frac{K_{1} + K_{2}}{2} = \ \frac{K_{1} + \frac{4K_{1}}{3}}{2}$
= $\frac{7K_{1}}{6}$
Hence , $\frac{K}{K_{1}} = \frac{7}{6}$

Q. Two rods of equal length and area of cross-section are kept parallel and lagged between temperature 20$℃$ and 80$℃$. The ratio of the effective thermal conductivity to that of the first rod is $\left\lbrack the\ ratio\ \left( \frac{K_{1}}{K_{2}} \right) = \frac{3}{4} \right\rbrack$

Explanation

Reviewed by Dr. Abubacker

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