Question

In capillary pressure below the curved surface of the water will be
A. Equal to atmospheric
B. Equal to upper side pressure
C. More than uppers side pressure
D. Lesser than upper side pressure

Answer 1

Hint: Capillary Pressure is the pressure difference current throughout the interface setting apart immiscible fluids. Radius is inversely proportional to height. $R\propto \dfrac{1}{h}$.
Where R is the radius of the tube and h is the height of the tube.




Complete answer:

For molecules in the interior:
Net forces = 0 in view that there are enough molecules round to balance out.

For molecules on the surface:
The internet result of forces is a pull towards the indoors causing a tangential tension on the surface
Capillarity rise is due to the tendency of liquids to upward thrust in tubes of small diameter in opposition to gravity. Capillarity fall is due to the depression of liquids in tubes of small diameter in competition with gravity.
The capillary motion arises due to the adhesive and cohesive forces. If the diameter decreases, higher can be the liquid upward thrust.


In capillary pressure below the curved surface of the water will be lesser than the upper side pressure because the surface is concave upwards. Hence, pressure is in excess above the curve in the upper surface of the liquid.

Hence, the correct option is (D).


Note: Capillary pressure is the pressure between two immiscible fluids in a thin tube, resulting from the interactions of forces between the fluids and the solid wall of the tube.