Q1: Transition from laminar flow to turbulent flow is aided by the

ANS:D - all (a), (b) & (c).

The transition from laminar flow to turbulent flow can be influenced by several factors, and the statement "all (a), (b) & (c)" is accurate. Let's break down each factor:

1. Surface Roughness and Curvature:
   • Surface roughness and irregularities on the walls of the pipe or channel can disturb the smooth flow of fluid, causing small disturbances or eddies to form. These disturbances can promote the transition from laminar to turbulent flow by initiating the breakup of laminar boundary layers.
2. Vibration:
   • Vibration or oscillations in the fluid or the container carrying the fluid can introduce disturbances that disrupt laminar flow patterns. These disturbances can trigger the transition to turbulent flow by causing flow instabilities.
3. Pressure Gradient and Compressibility:
   • An increase in the pressure gradient (pressure drop) along the flow direction can lead to higher flow velocities. This higher velocity can exceed the critical Reynolds number, initiating turbulent flow.
   • Compressibility effects can also influence the transition to turbulent flow, especially in gases where changes in density due to pressure changes can affect flow stability.

Conclusion:

Therefore, all of the factors mentioned (surface roughness and curvature, vibration, pressure gradient, and compressibility of the flowing medium) can aid in the transition from laminar flow to turbulent flow. Thus, the correct answer is all (a), (b) & (c). Each of these factors contributes to disturbances in the flow that disrupt laminar patterns and promote the onset of turbulent flow.