Q$1)$ A fluid with temperature$-$independent physical properties is in fully developed laminar flow horizontally between two flat surfaces placed a distance $2$ H apart. For the fluid temperature is uniform at $T=T_1.$ For $x>0,$ both wall temperatures maintained at fixed temperature $T_H.$ Obtain the differential equation for $T(x,y)$ and write the boundary conditions. Do not solve the equation. $($Hint: You can use general differential equations to eliminate the unnecessary terms.$)$