A metal frame of total length `50 cm` ad croos-sectional area `0.20 cm^(2)` froms five sides of a regular hexagon. The free ends are maintained at `20^(@)C` and `40^(@)C`. Find the rate of heat flow through a cross-section of the frame `(K = 50 W//m^(@)C)`

Explanation

Resistance, `R = (l)/(KA) = (0.10)/(50 xx 0.2 xx 10^(-4)) = 100^(@)C//W`
`R_(eq) = 5 R`
Heat current, `i= (40 - 20)/(R_(eq)) = (20)/(5 r) = (4)/(100) = 0.04 W`