Figures below show water flowing through a horizontal pipe from left to right. Note that the pipe in the middle is narrower. Choose the most appropriate depiction of water levels in the vertical pipes.

Step-by-step solution

By Bernoulli's equation for streamline flow, p + 1 2 ρ v 2 + ρ g h = a (constant) In given situation h = constant ∴ p + 1 2 ρ v 2 = constant When velocity of flow in narrow section increases, pressure decreases. So, current level in vertical tubes is as shown below.