Flow Through Pipes MCQ with answer and solution

Concept

In series pipes, the same discharge flows through every pipe, and the head losses add up.

Formula

Q = Q₁ = Q₂ = Q₃; H = h_f1 + h_f2 + h_f3 + minor losses

Step-by-step solution

1. In series, pipes are joined end to end, so there is only one flow path. 2. By continuity, the same discharge passes through each pipe: Q = Q₁ = Q₂ = Q₃. 3. Total head loss = sum of the losses in each pipe, so the loss is large. 4. Because of this large loss, pressure falls along the line and is low at the end. 5. So discharge is constant and pressure is low: option A.

Explanation

In series pipes the same water passes through every pipe, so discharge stays the same. Head losses in all the pipes add together. This large total loss makes the pressure drop, so the pressure is low.

Why the other options are wrong

B: discharge is the same in every pipe (not low), and pressure is not constant because it drops due to losses. C: the losses add up, so pressure falls; it does not become high. D: discharge is not high; the same discharge flows through each pipe.

Shortcut

Series means same Q and added head loss. Parallel means same head loss and added Q.

Common mistake

Mixing up series and parallel rules.