Question

14.When a clean lengthy capillary tube is dipped vertically in a beaker containing water, the water rises to a height of 8cm.What will happen if another capillary tube 4cm and same radius is dipped vertically in the same beaker containing water.(Angle of water is 0degrees)

Answer 1

Dear Student,

As we know,

$h=\frac{2Scos\theta }{r\rho g}.....\left(1\right)$
S is the surface tension
$\theta$ is the angle of contact
r is the radius of a capillary
$\rho$ is the density of water
g is the acceleration of gravity

After inserting the new capillary of height 4 cm the rise in the water will be given by

$h\text{'}=\frac{2Scos\theta \text{'}}{r\rho g}.....\left(2\right)$
on comparing equation 1 and 2

$$\begin{gathered} \frac{h}{cos\theta }=\frac{h\text{'}}{cos\theta \text{'}} \\ \frac{8\mathrm{cm}}{cos0°}=\frac{h\text{'}}{\cos 0°} \\ h\text{'}=8cm\times 1 \end{gathered}$$

Therefore, water will flow out like a fountain .