The following observations were made in an experiment with Poiseuille's apparatus: Diameter of tube = 0.1 cm Density of liquid=2.4 g/cm""^(3) Volume of liquid collected per minute = 10 cm^(3) Pressure head of liquid = 25 cm Length of tube = 20 cm Using the above data, calculate the viscosity of the liquid.

The following observations were made in an experiment with Poiseuille'

1.	The following observations were made in an experiment with Poiseuille's apparatus: Diameter of tube = 0.1 cm Density of liquid=2.4 g/cm""^(3) Volume of liquid collected per minute = 10 cm^(3) Pressure head of liquid = 25 cm Length of tube = 20 cm Using the above data, calculate the viscosity of the liquid.
Answer» SOLUTION :The volume Q of liquid flowing out per second through the capillary tube is `Q=(pi Pr^(4))/(8 eta l)` where `P/l` is the pressure gradient r is the radius of the tube `eta ` is the viscosity Given, `Q =10 CM^(3)" per MINUTE "= 10/60 cm^(3)` per s `P=hpg =25 xx 2.4 xx 980` l=20 cm `r=(0.1 cm)/(2)=0.05 cm` `n=?` `eta=(pi Pr^(4))/(8 l Q)` `=(3.14 xx 25 xx 2.4 980 xx (0.05)^(4) xx 60)/(8 xx 20 xx 10)` =0.043 cgs unit