A capillary tube is dipped in water. Calculate the weight of water raised in capillary above the normal level due to capillary action. Surface tension of water is 72 dyne cmº. The radius of capillary tube is 0.3 mm.

Explanation

r=0.3 mm=0.03 cm
`T=72"dyne cm"^(-1)`
`p=1 g cm^(-3)`
`theta=0^(@), g =980 cms^(-2)`
`h=(2T cos theta)/(rpg)`
`=(2 xx 72 xx 1)/(0.03 xx 1 xx 980)=4.8cm`
Weight of water raised `=mg=pir^(2) hpg`
`=3.14 xx (0.03)^(2) xx 4.8 xx 1 xx 980`
=13.29 dyne
=0.01 gwt