In a heat exchanger, it is observed that $$\Delta {T_1} = \Delta {T_2},$$ where $$\Delta {T_1}$$ is the temperature difference between the two single phase fluid streams at one end and $$\Delta {T_2}$$ is the temperature difference at the other end. This heat exchanger is

In a condenser of a power plant, the steam condenses at a temperature of $${60^ \circ }C.$$ The cooling water enters at $${30^ \circ }C$$ and leaves at $${45^ \circ }C.$$ The logarithmic mean temperature difference $$(LMTD)$$ of the condenser is

For the same inlet and outlet temperatures of hot and cold fluids, the Log mean temperature Difference $$(LMTD)$$ is

The practice to use steam on the shell side and cooling water on the tube side in condensers of steam power plant is because