An incompressible fluid flows steadily through a cylinder pipe which h

1.	An incompressible fluid flows steadily through a cylinder pipe which has 2r at point A and radius r at B further along the flow direction. If the velocity at point A is v, its velocity at point B isA) 2v B) v C) v/2 D) 4v
Answer» D) 4v Explanations: At point A, radius is 2r and at point B, radius is r. Area × velocity = constant Hence πr² × V = constant i.e. r₁ ²V₁= r₂ ²V₂ Given r1 = 2r r₂ = r V₁ = V V₂ =? ∴ (2r)² × V = r² ∙ V₂ ∴ V₂ = 4V V₂ means velocity at point B i.e. V-B = 4V

An incompressible fluid flows steadily through a cylinder pipe which has 2r at point A and radius r at B further along the flow direction. If the velocity at point A is v, its velocity at point B isA) 2v B) v C) v/2 D) 4v

Answer»

D) 4v

Explanations:

At point A, radius is 2r and at point B, radius is r.

Area × velocity = constant

Hence πr² × V = constant

i.e. r₁ ²V₁= r₂ ²V₂

Given r1 = 2r

r₂ = r

V₁ = V

V₂ =?

∴ (2r)² × V = r² ∙ V₂

∴ V₂ = 4V

V₂ means velocity at point B i.e.

V-B = 4V