Question

Consider the need to insulate a flat wall using three different insulating materials, each having the same thickness. The materials have constant thermal conductivities, k, of 1, 2, and 3 Wm-1 K-1 . You are asked to advise workers on the proper installation order of the three materials so that the final composite will be the most effective at reducing heat loss from the wall. Which statement is true

Answer 1

Answer: The options related to your question is missing attached below is the missing option

a.) The insulation must be arranged in order of increasing k starting with the lowest k material at the wall surface.

b.) The insulation must be arranged in order of decreasing k starting with the highest k material at the wall surface.

c.) The insulation can be arranged in any order.

d.) It is impossible to decide because the temperatures are not specified and the order will depend on the ∆T.

e) The insulation with the lowest k should be nearest the wall, and the order of the other two is irrelevant.

answer:

The insulation must be arranged in order of increasing k starting with the lowest k material at the wall surface. ( A )

Step-by-step explanation:

The correct statement is ; The insulation must be arranged in order of increasing k starting with the lowest k material at the wall surface.

Because the insulation has to be arranged following the order of it's increasing thermal conductivity ( K-value )