#### Heat Transfer

Q.
For a counter current heat exchanger with Tih = 80^circC, T^circc= 60^circC, T^circh = 50^circC andTic = 30^circC, and the temperature difference between the two streams being the same everywhere along Z, the direction of flow of hot fluid. The temperature profile should satisfy

A. (d^2T)/(dZ^2) > 0
B. (d^2T)/(dZ^2) = 0
C. (d^2T)/(dZ^2) < 0
D. (dT)/(dZ) = 0