NEET 2022 Model Paper 5

Concept:By Bernoulli's theorem, where cross-section is smaller, velocity is higher and pressure is lower.Explanation:The tube shown has a narrow constriction in the middle and wider sections on both sides.By the equation of continuity: $Av = \text{constant}$, so at the narrow section, velocity $v$ is higher.By Bernoulli's equation: $P + \frac{1}{2}\rho v^2 = \text{constant}$, higher velocity → lower pressure.So the pressure variation along $x$ should be:High pressure at the wide left sectionDrops at the narrow middle constrictionRises back at the wide right sectionThis gives a graph that starts high, dips down in the middle (at the constriction), and returns to a higher value — a smooth dip shape.Option C shows exactly this: pressure starts at a certain level, decreases at the constriction, and then recovers — a smooth dip (trough) in the middle.Answer:Option **C** — Pressure dips at the narrow constriction and recovers at the wider sections.