Question

Given that the surface tension of water is $75dyne/cm$, its density $1g/cc$ and angle of contact zero, the height to which water rises in a capillary tube of $1mm$ diameter is take $g=10m/s^2$

• A. $9.0cm$
• B. $7.5cm$
• C. $6.0cm$
• D. $3.0cm$

Answer 1

The correct option is D $3.0cm$

The height to which water rises in a capillary tube can be calculated using following formula, $h=\frac{4Scos\theta }{\rho gd}$

where given , surface tension of water $=S=75dyne/cm$, angle of contact $=\theta =0$, density of water $=\rho =1g/cc$, acceleration due to gravity $=g=10m/s^2=1000cm/s^2$ and diameter of tube $=d=1mm=0.1cm$

Thus, $h=\frac{4\times 75\times cos0}{1\times 1000\times 0.1}=3cm$