$(10$ pt$)2.$ Consider one$-$dimensional conduction in a plane composite wall. The outer surfaces are exposed to a fluid at $23C$ and a convection heat transfer coefficient of $8000\frac{W}{m^2}*K.$ The middle wall B experiences uniform heat generation $q_B^{},$ while there is no generation in walls A and C $.$ The temperatures at the interfaces are $T_1=251C$ and $T_2=221C.$ Consider $k_A=22\frac{W}{m}*K,k_C=15\frac{W}{m}*K,L_A=20mm,L_B=20mm,$ and $L_C=15mm.$

Assuming negligible contact resistance at the interfaces, determine the volumetric heat generation $q_B^{}.$