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A 2.5 m-high, 4-m-wide, and 80-cm-thick wall of a house has a thermal resistance of 0.0125°c/W. The thermal conductivity of the wall is (a) 3.2 W/mK (b) 4.8 W/m-K (c) 6.4 W/m-K (d) 1.6 W/m-K (e) 32 W/m-K

Respuesta :

Answer:

The correct answer is part 'c': 6.4 W/m-K

Explanation:

We know that the thermal resistance of a wall is given by

[tex]R_{wall}=\frac{L}{kA}[/tex]

where,

L = thickness of wall

k = thermal conductivity of wall

A = Surface area of wall

Applying values we get

[tex]k=\frac{L}{R_{wall}A}[/tex]

[tex]k=\frac{80\times 10^{-2}}{0.0125\times 2.5\times 4}\\\\\therefore k=6.4W/mK[/tex]