The cylindrical tube of a spray pump has radius R, one end of which has n fine holes, each of radius r. If the speed of the liquid in the tube is V, the speed of the ejection of the liquid through the holes is:

A $\frac{V^2R}{nr}$

B $\frac{VR^2}{n^2r^2}$

C $\frac{VR^2}{nr^2}$

D $\frac{VR^2}{n^3r^2}$

The answer is C.

Solution

Equation of continuity: $Av$ = constant
$\pi R^2V = n\pi r^2v_1$
$v_1 = \frac{VR^2}{nr^2}$

Concept Av = constant

34 questions from this chapter have appeared across 14 exam years.