ANS:B - turbulent flow

If velocities of fluid particles vary from point to point in magnitude and direction, as well as from instant to instant, the flow is said to be turbulent flow. Turbulent flow is characterized by chaotic and irregular movement of fluid particles, resulting in fluctuations in velocity, pressure, and other flow properties. In turbulent flow, eddies and vortices form, causing mixing and random motion of fluid particles throughout the flow field. In contrast, laminar flow is characterized by smooth, orderly movement of fluid particles in parallel layers, with minimal mixing between layers. In laminar flow, fluid particles move in straight paths along streamlines, and the velocity profile remains constant across the flow. Therefore, if velocities vary both in magnitude and direction from point to point and instant to instant, it indicates turbulent flow.