Q1: Evaporator tubes are generally

ANS:B - vertical

Evaporator tubes can be found in various orientations depending on the design and application of the evaporator system. However, they are often installed vertically or horizontally. Vertical evaporator tubes are commonly used in applications where gravity can assist in draining the liquid condensate produced during the evaporation process. In such systems, the vapor typically rises while the liquid condensate falls due to gravity. Horizontal evaporator tubes are frequently employed in situations where space constraints or other design considerations dictate a horizontal layout. In horizontal evaporators, the vapor and liquid phases may travel parallel to the ground. Inclined or sloped evaporator tubes are less common but can be utilized in specialized applications to take advantage of gravity or other factors to facilitate the flow of vapor and liquid. The term "random" doesn't typically describe the orientation of evaporator tubes, as it implies a lack of specific orientation or pattern. However, in some cases, the tubes may be arranged randomly within the evaporator vessel for specific purposes such as maximizing heat transfer or promoting mixing. Therefore, the most common orientations for evaporator tubes are horizontal and vertical, with inclined tubes being less common and random arrangements being less typical and more specialized.