Two rods of equal lengths and areas of cross-section are kept parallel and hanged between temperatures 20$℃$ and 80$℃$. The ratio of the effective thermal conductivity to that of the first rod is (the ratio=$\frac{K_{1}}{K_{2}}$ =$\frac{3}{4}$ )

Question

Dr. Abubacker · Accepted Answer

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

Q. Two rods of equal lengths and areas of cross-section are kept parallel and hanged between temperatures 20$℃$ and 80$℃$. The ratio of the effective thermal conductivity to that of the first rod is (the ratio=$\frac{K_{1}}{K_{2}}$ =$\frac{3}{4}$ )

Explanation

Reviewed by Dr. Abubacker

Want more practice?