A large bottle is fitted with a siphon made of capillary glass tubing. Compare the times taken to empty the bottle when it is filled. (i) with water (ii) with petrol of density 0.8 cgs units. The viscosity of water and petrol are 0.1 and 0.2 cgs units repectively.

Explanation

The volume of liquid flowing in time t through a capillary tube is given by
`V=Qt=(pi Pr^(4)t)/(8 eta l)=(pi h rho gr^(4)t)/(8 etal)`
`:.` For Water `V_(1)=(pi h rho_(1)gr^(4)t_(1))/(8l eta_(1))`
For petrol , `V_(2)=(pi h rho_(2)gr^(4)t_(2))/(8l eta_(2))`
But `" " V_(1)=V_(2)`
`:. " " (pi h rho_gr^(4)t_(1))/(8l eta_(1))=(pi h rho_(2)gr^(4)t_(2))/(8l eta_(2))`
`or " "(t_(1))/(t_(2))=(eta_(1))/(eta_(2))xx (rho_(1))/(rho_(2))=(0.01)/(0.02)xx(0.8)/(0.02)xx(0.8)/(0.02)=0.4`