ANS:A - 1/^-0.8

In case of surface condensers, a straight line is obtained on plotting temperature difference (ΔT) on an ordinary graph paper. The temperature difference (ΔT) between the temperature of the cooling water inlet and the temperature of the condensing vapor outlet is a key parameter in surface condensers. When plotted on an ordinary graph paper against other variables such as heat transfer rate or cooling water flow rate, a straight line is typically observed. This straight line behavior is characteristic of the heat transfer process in surface condensers, and it helps in analyzing and optimizing the performance of the condenser system.