Calculate the density of paraffin oil. If within a glass capillary tube of radius 0.25 mm dipped in paraffin oil of surface tension 0.0245 N/m, to a height of 2cm. [ Angle of contact of paraffin oil with glass = `28^(@) `]

Explanation

Data : r = 0.25 mm = ` 2.5 xx 10^(-4) m` T = 0.0245 N/m
` h= 2cm = 2 xx 10^(-2) m , theta = 28^(@) ,g = 9.8 m//s^(2)`
` T = (hr rhog)/(2 cos theta)`
` rho = (2T cos theta)/(hrg) = (2xx 0.0245 xx cos 28^(@))/(2 xx 10^(-2) xx 2.5 xx 10^(-4) xx 9.8)`
` (0.0245 xx 0.8829)/(2.5 xx 9.8 xx 10^(-6)) = 882.9 " kg/m"^(3)`
This gives the density of paraffin oil.