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Steam at 373 K is passed through a tube ...

Steam at 373 `K` is passed through a tube of radius `10 cm` and length` 10 cm` and length `2m`. The thickness of the tube is `5mm` and thermal conductivity of the material is` 390 W m^(-1) K^(-1)`, calculate the heat lost per second. The outside temperature is `0^(@)C`.

Text Solution

Verified by Experts

Using the relation `Q = '(KA(T_(1)-T_(2))t)/(L)`
Here , heat is lost through the cylindrical surface of the tube .
`A=2pir ("radius of the tube" ) ("length of the tube")=2pi xx0.1xx2=0.4pim^(2)`
`K=390 W m^(-1) K^(-1)`
` T_(1)=373 K, T_(2) =0^(@)C=273K, L=5mm =0.005m` and ` t=1s`
`therefore Q=(390xx0.4pixx(373-273)xx1)/0.005 = (390xx0.4pixx100)/0.005 = 98xx10^(5)J.`
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