Question

A non viscous liquid is flowing through a frictionless duct, with cross-section varying as shown in figure.

Which of the following graph represents the variation of pressure $p$ along the axis of tube?

• A.
• B.
• C.
• D.

Answer 1

Answer: (B)

As we know according to equation of continuity, when cross-section of duct decreases, the velocity of flow of liquid increases and in accordance with Bernoulli's theorem, in a horizontal pipe, the place where speed of liquid is maximum, the value of pressure is minimum. Hence the $2^{\text{nd }}$ graph correctly represents the variation of pressure.