When a vertical capillary of length with the sealed upper end was brought in contact with the surface of a liquid, the level of this liquid rose to the height `h`. The liquid density is `rho`, the inside diameter the capillary is `d`, the contact angle is `theta`, the atmospheric pressure is `rho_(0)`. Find the surface tension of the liquid. (Temperature this process remains constant.)

Answer

`(P_(0))/(4costheta)`

Explanation

Applying Boyle's law
`p_(0)Al=[(P_(0)-hrhog)+(4T)/dcostheta]a(L-h)`
`T=(P_(0))/(4costheta)[(h/(L-h))+hrhog]d`