NEETPhysicsMechanical Properties of Fluids
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): In a horizontal venturi-meter, the fluid pressure is minimum at the narrowest cross-section (throat). Reason (R): According to the equation of continuity, fluid velocity is maximum at the narrowest cross-section, and by Bernoulli's principle, an increase in velocity is accompanied by a decrease in
Options
- ABoth (A) and (R) are correct and (R) is the correct explanation of (A)
- BBoth (A) and (R) are correct but (R) is not the correct explanation of (A)
- C(A) is correct but (R) is not correct
- D(A) is not correct but (R) is correct
Correct answer
A. Both (A) and (R) are correct and (R) is the correct explanation of (A)
Step-by-step solution
For an incompressible fluid flowing through a horizontal pipe, the equation of continuity states that A₁ v₁ = A₂ v₂ . At the narrowest cross-section (throat), the area A is minimum, so the fluid velocity v is maximum. According to Bernoulli's principle for a horizontal flow, P + 1 2 v^2 = constant . Since the velocity is maximum at the throat, the pressure P must be minimum to keep the sum constant. Therefore, both Assertion and Reason are correct, and the Reason correctly explains the Assertion. Answer: Both (A) a