Figure shows the cross section of a wall made of three layers. The layer thicknesses are `L_(1), L_(2) = 0.750L_(1), ` and `L_(3) = 0.350L_(1)`. The thermal conductivities are `k_(1), k_(2) = 0.900k_(1)`, and `k_(3) = 0.800k_(1)`. The temperature at the left side and right side of the wall are `T_(H) = 30.0^(@)C` and `T_(C)= - 15.0^(@)C`, respectively. Thermal conduction is steady . (a) What is the temperature difference `Delta T_(2)` across layer 2 ( between the left and right sides of the layer ) ? If `k_(2)` were, instead, equal to 1.1`k_(1)`, (b) would the reate at which energy is conducted through the wall be greater than, less than, or the same as proviously, and (c ) what would be the value of `Delta T_(2)` ?

Explanation

(a) `16.5^(@)C`, (b) greater conductivity should mean a larger rate of conductive heat transfer , (c ) `14.5^(@)C`