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
Correct answer: B. 12 m/s.
- A. 3 m/s.
- B. 12 m/s.
- C. 18 m/s.
- D. 24 m/s.
Explanation
The principle of conservation of mass for a fluid in a closed system is given by the equation: A1 * V1 = A2 * V2, where A1 and V1 are the initial area and velocity, and A2 and V2 are the final area and velocity. Initially, the fluid flows with an area of 6 m² and a velocity of 8 m/s, so A1 * V1 = 6 * 8 = 48. When the area decreases to 4 m², applying the equation gives 48 = 4 * V2, solving for V2 gives V2 = 12 m/s. Therefore, the correct answer is Option B: 12 m/s. The other options do not satisfy this equation and therefore are incorrect.
Last updated
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.
Exams that ask Physics questions like this
Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
A pipe varies uniformly in diameter from 2m to 4m. An incompressible fluid enters the pipe with velocity 16 m/s. What is velocity of fluid when it leaves the pipe?
A rocket is made to travel at a high speed by making the ejection nozzle narrow. This phenomenon is based on
According to equation of continuity A1V1 = A2V2 = constant. The constant is equal to_______________?
According to the equation of continuity, if the cross-sectional area of a pipe decreases, then the speed of the fluid passing through it
An incompressible fluid flows through a pipe that becomes narrower in one section. The fluid speed increases in that region to maintain: