(i) One end of a uniform glass capillary tube of radius `r = 0.025` cm is immersed vertically in water to a depth `h = 1cm`. Contact angle is `0^(@)`, surface tension of water is `7.5 × 10–2 N//m`, density of water is `rho = 10^(3) kg//m^(3)` and atmospheric pressure is `P_(o) = 10^(5) N // m^(2)`

Find the excess pressure to be applied on the water in the capillary tube so that -
(a) The water level in the tube becomes same as that in the vessel.
(b) Is it possible to blow out an air bubble out of the tube by increasing the pressure? (ii) A container contains two immiscible liquids of density `rho_(1)` and `rho_(2) (rho_(2) gt rho_(1))`. A capillary of radius r is inserted in the liquid so that its bottom reaches up to denser liquid and lighter liquid does not enter into the capillary. Denser liquid rises in capillary and attain height equal to h which is also equal to column length of lighter liquid. Assuming zero contact angle find surface tension of the heavier liquid.

Answer

(1) (a) `600 P_(a)` (b) Yes (3) `T=r/2(rho_(2)-rho_(1))gh`