According to the equation of continuity, if the cross-sectional area of a pipe decreases, then the speed of the fluid passing through it
Correct answer: A. Increases
- A. Increases
- B. Decreases
- C. Remains the same
- D. Varies unpredictably
Explanation
The equation of continuity states that the mass flow rate must be constant in a closed system. This means that the product of cross-sectional area and fluid speed at any point in the pipe must remain constant. Therefore, if the cross-sectional area decreases, the fluid speed must increase to maintain the same mass flow rate. Option A is correct. Option B is incorrect because a decrease in area results in an increase in speed, not a decrease. Option C is incorrect because the speed does not remain the same; it changes to conserve mass. Option D is incorrect because the change in speed is predictable and follows the principle of mass conservation.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Equation of Continuity
The equation of continuity expresses conservation of mass in fluid flow. For steady incompressible flow, Av remains constant, so fluid speed increases when the cross-sectional area decreases; for compressible flow, ρAv is constant. This relation describes flow rate and area-speed changes without including pressure effects from Bernoulli’s equation.
Practise Fluid Dynamics
363 free Fluid Dynamics MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Physics questions like this
Physics is on 16 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Equation of Continuity questions
In a cement factory, a viscous liquid flows through a pipe with an area of cross-section 6 m² at a velocity of 8 m/s.When this fluid moves forward, the area of cross-section of the pipe decre velocity of the liquid will now be 4 m² The
The equation of continuity of a fluid is related to the conservation of
In a cement factory, a viscous liquid flows through a pipe with an area of cross-section 6 m2 at a velocity of 8 m/s.When this fluid moves forward, the area of cross-section of the pipe decreases to 4 m2 The velocity of the liquid will now be
In a fire fighting machine, a jet is attached to the head of water pipes to increase the
An industrial liquid flows through a section of a pipe with an area of cross-section 2 m2 at a velocity of 10 m/s. If at a certain section the area of cross-section decreases to 1 m2, then the velocity of the liquid will be
In a cement factory, a viscous liquid flows through a pipe with an area of cross-section 6 m2at a velocity of 8 m/s. When this fluid moves forward, the area of cross-section of the pipe decreases to 4 m2 The velocity of the liquid will now be