Question

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

Answer 1

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

Step-by-step explanation:

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

`R_(wall)=(L)/(kA)`

where,

L = thickness of wall

k = thermal conductivity of wall

A = Surface area of wall

Applying values we get

`k=(L)/(R_(wall)A)`

`k=(80* 10^(-2))/(0.0125* 2.5* 4)\\\\\therefore k=6.4W/mK`