Minor head losses are caused by?

Minor head losses in a fluid system occur due to factors that are not directly related to the length of the pipe itself. Sudden changes in direction or velocity of flow—such as bends, fittings, valves, and other obstructions—create turbulence and disrupt the smooth flow of water. These disruptions lead to energy losses as the fluid passes through these changes, resulting in minor head losses.

While the other options mention contributing factors to head loss, they primarily address issues associated with friction and roughness over lengths of pipe or the accumulation of deposits. These factors can lead to major head losses, which are more significant than minor head losses. In contrast, minor head losses specifically pertain to the localized effects of flow disturbances, making sudden changes in direction or velocity the primary cause. Understanding this distinction is key when analyzing fluid systems and their efficiency.