[amp_mcq option1=”is constant over the cross-section” option2=”varies linearly from zero at walls to maximum at centre” option3=”varies parabolically with maximum at the centre” option4=”none of the above” correct=”option3″]
The correct answer is: C. varies parabolically with maximum at the centre.
The velocity distribution for laminar flow through a circular tube is parabolic, with the maximum velocity at the center of the tube and zero velocity at the walls. This is because the fluid particles near the walls are in contact with the walls and cannot move, while the fluid particles in the center of the tube are not in contact with the walls and can move freely. The velocity of the fluid particles decreases as they move towards the walls, due to the friction between the fluid particles and the walls.
Option A is incorrect because the velocity of the fluid particles is not constant over the cross-section of the tube.
Option B is incorrect because the velocity of the fluid particles does not vary linearly from zero at the walls to maximum at the center.
Option D is incorrect because the velocity distribution for laminar flow through a circular tube is parabolic.