+91-8076753736[email protected]
logo
logo
-->

Mechanical Properties Of Fluids

Question
CBSEENPH11026250
Wired Faculty App

The cylindrical tube of a spray pump has a cross-section of 8 cm2 , one end of which has 40 fine holes each of area 10-8 m2. If the liquid flows inside the tube with a speed of 0.15 m min-1 the speed with which the liquid is ejected through the holes is

  • 50 m/s

  • 5 m/s

  • 0.05 m/s

  • 0.5 m/s

Solution

B.

5 m/s

One of the fundamental principles used in the analysis of uniform flow is known as continuity of flow. This principle is derived from the fact that mass is always conserved in fluid systems regardless of the pipeline complexity or direction of flow.

According to the equation of continuity,

          Q = A1 V1 = A2 V2

                  a v = constant                       ... (i)

Where Q is the volumetric flow rate

         A is the cross-sectional area of flow

          V is the mean velocity

Area of cross secrction of the spray pump,

a1 = 8 cm2 = 8 × 10-4 m2

number of holes n = 40

          v1 = 0.15 m min-1 = 0.1560

         ∴   For tube, 

            8 × 10-4 × 0.1560 = a1 v1

    For holes,

             40 × 10-8 × v   = a2 v2 

According to law of continuity from equation (i)

∴                a2 v2  = a1 v1

∴         40 × 10-8 × v  = 8 × 10-4 × 0.1560

⇒                   v = 8 × 10-4 × 0.1540 × 10-8 × 60

⇒                    v = 5 m/s

Some More Questions From Mechanical Properties of Fluids Chapter

A jar filled with two non-mixing liquids 1 and 2 having densities ρ1 and ρ2 respectively. A solid ball, made of a material of density ρ3, is dropped in the jar. It comes to equilibrium in the position shown in the figure.
Which of the following is true for ρ1, ρ2 and ρ3?

A capillary tube (A) is dropped in water. Another identical tube (B) is dipped in a soap water solution.Which of the following shows the relative nature of the liquid columns in the two tubes? 

A 20 cm long capillary tube is dipped in water. The water rises up to 8 cm. If the entire arrangement is put in a freely falling elevator the length of water column in the capillary tube will be

Spherical balls of radius R are falling in a viscous fluid of viscosity η with a velocity v. The retarding viscous force acting on the spherical ball is

If two soap bubbles of different radii are connected by a tube,

A steam of a liquid of density ρ flowing horizontally with speed v rushes out of a tube of radius r and hits a vertical wall nearly normally. Assuming that the liquid does not rebound from the wall, the force exerted on the wall by the impact of the liquid is given by

A wide hose pipe is held horizontally by a fireman. It delivers water through a nozzle at one litre per second. On increasing the pressure. this increases to two litres per second. The firman has now to

Mock Test Series

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation