Q1: The equivalent diameter for pressure drop is __________ that for heat transfer.

ANS:A - smaller than

The equivalent diameter for pressure drop is typically smaller than that for heat transfer. In heat transfer analysis, the equivalent diameter is often used to account for the geometry of a non-circular duct or tube when calculating heat transfer coefficients. This equivalent diameter is based on the hydraulic diameter, which takes into account the cross-sectional area and perimeter of the duct or tube. In contrast, when analyzing pressure drop in fluid flow through a non-circular duct or tube, the equivalent diameter used is typically based on the cross-sectional area alone. This can result in a smaller equivalent diameter for pressure drop calculations compared to that used for heat transfer. Therefore, the correct statement is: "smaller than."