Diameters of the arms of a U tube are 10 mm and 1 mm . It is partially filled with water and it is held in a vertical plane . Find the difference in heights of water in both the arms . (Surface tension of water =70 dyne `cm^(-1)` angle of contact `=0^(@).g=980cms^(-2))`

Explanation

`r_(1)=(d_(1))/(2)=5mm=0.5cm`
`r_(2)=(d_(2))/(2)=0.05cm`
`T=70"dyne"//cm`
`theta=0`
`rho=1g//cm^(3)`
`rho=1g//cm^(3)`
`g=980cm//s^(2)`
`T=(rhrhog)/(2costheta)`
`thereforeh=(2Tcostheta)/(rrhog)`
`thereforeh=h_(2)-h_(1)`
`thereforeh=(2Tcostheta)/(rhog)[(1)/(r_(2))-(1)/(r_(1))]`
`=(2xx70xxcos0^(@))/(1xx980)[(1)/(0.05)-(1)/(0.5)]`
`=(1)/(7)[20-2]`
`thereforeh=(18)/(7)=2.57//cm`