Find the excess pressure inside (a) a drop of mercury of radius 2 mm (b) a snap bubble of radius 4 mm and (c) an air bubble of radius 4 mm formed inside a tank of water. Surface tension of mercury, soap solution and water are 0.465 N m-1, 0.03 N m-1 and 0.076 N m-1 respectively.

(a) 465 N m-2

(b) 30 N m-2


(c) 38 N m-2


(a) Surface tension of mercury,


Radius of drop,


Excess pressure is given by


(b) Surface tension of soap,


Radius of drop,


Excess pressure is given by


(c)Surface tension of water,


Radius of air bubble,


Excess pressure is given by


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