Question

A plane brick wall (K = 0.7 W/m*K) is 10 cm thick. The thermal resistance of this wall per unit of wall area is

A. 0.524 m²*K/W
B. 0.143 m²*K/W
C. 0.448m²*K/W
D. 0.327 m²*K/W
E. 0.250 m²*K/W

Answer 1

The thermal resistance of the 10 cm thick brick wall with a thermal conductivity of 0.7 W/m*K is 0.143 m²*K/W, calculated using the formula for thermal resistance R = L / (K × A), leading to answer B.

Step-by-step explanation:

The question asks about the thermal resistance of a brick wall given its thermal conductivity (K = 0.7 W/m*K) and its thickness (10 cm). Thermal resistance is a measure of a material's ability to resist heat flow and is calculated using the formula:

R = L / (K × A)

Where R represents the thermal resistance, L is the thickness of the material, K is the thermal conductivity, and A is the area. Here, the area A is cancelled out since we're looking for thermal resistance per unit area. Thus, we only need to consider the thickness and the thermal conductivity of the material.

Converting 10 cm to meters (10 cm = 0.10 m), the calculation becomes:

R = 0.10 m / (0.7 W/m*K)
= 0.143 m²*K/W

Therefore, the correct answer is B. 0.143 m²*K/W.