Water flows in a horizontal pipe whose one end is closed with a valve. The reading of the pressure gauge attached to the pipe is P 1 . The reading of the pressure gauge falls to P 2 when the valve is opened. The speed of water flowing in the pipe is proportional to

Physics · Fluid Mechanics

JEE Main 2025 — 23 January, Evening Shift — Question 55

Water flows in a horizontal pipe whose one end is closed with a valve. The reading of the pressure gauge attached to the pipe is $\mathrm{P}_{1}$ . The reading of the pressure gauge falls to $\mathrm{P}_{2}$ when the valve is opened. The speed of water flowing in the pipe is proportional to

Option A:
$\sqrt{\mathrm{P}_{1}-\mathrm{P}_{2}}$
Correct
Option B:
$\left(P_{1}-P_{2}\right)^{2}$
Option C:
$\left(\mathrm{P}_{1}-\mathrm{P}_{2}\right)^{4}$
Option D:
$P_{1}-P_{2}$

Answer: A

Step-by-step solution

By Bernoulli equation

$P_{1}+\frac{1}{2} \times \rho \times 0^{2}=P_{2}+\frac{1}{2} \rho V^{2}$

$\mathrm{v}=\sqrt{2 \rho\left(\mathrm{P}_{1}-\mathrm{P}_{2}\right)}$

Answer key and solution verified before publishing.

Practise Fluid Mechanics

Start with this question, then two more from the same chapter — with a tutor that explains every step. Free.

Solve a similar one free

Exam: JEE Main 2025
Paper: 23 January, Evening Shift
Subject: Physics
Chapter: Fluid Mechanics
Topic: Bernoulli's Equation and its Applications