Lower end of a capillary tube of radius r is placed vertically in water of density d.Surface tension S.The rise of water in the capillary tube is upto height h,then heat evolved is?

Dear Abhranil,

let x be the angle of contact then...
force of surface tension=2.pie.r.S.cosx
displacement=h
Work done by surfave tension=2.pie.r.h.S.cosx
also work done against Gravity=mgh=pie.(rh)^2.d.g.
Heat evolved =Difference in work done= 2.pie.r.cosx.S - pie.d.g.(rh)^2
=> pie.r [ 2.S.cos x - d.g.r.(h^2) ]
(ANS)


If angle of contact is 0 then put x=0 to get the req. ans.


Regards.

If angle of contact is 0 then put x=0 to get the req. ans.