In a turbulent flow, the velocity of the liquid molecules in contact with the walls of the tube is

The correct option is "May have any value".

Step-by-Step Explanation:

1. Understanding Streamline vs. Turbulent Flow:
In a steady or streamline flow of a fluid through a tube, the fluid moves in orderly layers. The layer of the liquid in direct contact with the walls of the tube is at rest due to adhesive forces between the liquid molecules and the tube walls. This is known as the "no-slip condition," where the velocity of the liquid molecules in contact with the walls is zero.

2. Behavior in Turbulent Flow:
When the velocity of the liquid exceeds a certain threshold called the critical velocity, the flow becomes turbulent. In turbulent flow, the motion of the fluid molecules becomes highly irregular, chaotic, and disordered.

3. Velocity at the Boundary:
Due to the continuous formation and collision of eddies, vortices, and rapid mixing in turbulent flow, the molecules are constantly deflected in random directions. The fluid molecules at or very near the walls do not maintain a steady state of rest. Instead, because of intense mixing and chaotic collisions, the velocity of the liquid molecules in contact with the walls of the tube is constantly fluctuating and can vary rapidly. Therefore, the velocity of these molecules may have any value at any given instant.