Question

Water is flowing through a horizontal pipe in streamline flow. At the narrowest part of the pipe______-

• A. Velocity is max and pressure is min.
• B. Pressure is max and velocity is min.
• C. Both pressure and velocity are max.
• D. Both the velocity and pressure are min.

Answer 1

Answer: (A)

According to Bernoulli's theorem, for stream line flow through horizontal pipe.
$p+\frac{1}{2} \rho V^{2}=\ldots$ (i) constant
where, $p=$ pressure,
$v=$ velocity of liquid
and $\rho=$ density of liquid.
Hence, according to principle of continuity, at narrowest part of the pipe, velocity is maximum. Hence from Eq. (i), pressure is minimum at narrowest part of the pipe.