Question

An ice box is made of wood 1.75 cm thick lined inside with cork 2 cm thick. If the temperature of inner surface of the cork is steady at 0 degree celsius and that of outer surface of wood is 12 degree celsius, what is the temperature of interface?

Answer 1

Answer :- 10.2° C

Thickness of wood = d = 1.75 cm = 0.0175 m

Thickness of cork = 2 cm = 0.02 m

During steady state,

( Q/t ) w = (Q/t) c  ---here w = wood, c = cork

[KA(Θ1 - Θ2)/d] wood  = [KA(Θ1 - Θ2)/d ] cork

5KA(12-Θ) / 0.0175 = KAΘ /0.02

Solving, above we get Θ = 10.2° C