Figure shows in cros section a wall consisting of four layers with thermal conductivities `K_(1)=0.06W//mK`
`K_(3)=0.04W//mK` and `K_(4)=0.10W//mK`. The layer thicknesses are `L_(1)=1.5cm,L_(3)=2.8` cm and `L_(4)=3.5cm` the temperature of interfaces is as shown in figure. energy transfer through the wall is in steady state.
Q. The temperature of the inteface between layers 2 and 3 is

Options

A. `11^(@)C`
B. `8^(@)C`
C. `7.2^(@)C`
D. `5.4^(@)C`

Explanation

` (triangleQ)/(trianglet)|_("layer 1")` = `(triangleQ)/(trianglet)|_("layer 3")`
`implies(0.06xxAxx5)/(1.5xx10^(-2))=(0.04xxAxxtriangleT)/(2.8xx10^(-2))impliesDT=14^(@)C`
`T_(3)=(-3+14)^(@)C=11^(@)C`