#8 Capillary Action

#8 Capillary Action

  10:37 PM    Unknown

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The rise or fall Of a liquid in a capillary tube is related to the surface tension of a liquid whether a liquid rise in a capillary like water or depressed like mercury. It depends on the relative magnitude of cohesive and adhesive forces.These forces determine the contact angle which the liquid make with the walls Of the tube.

If the contact angle is less than 90° it is said to wet surface and concave miniscus is Formed.

If contact angle is Greater than 90° the liquid doesn't wet the surface and convex miniscus is formed.

The formation of concave miniscus by a liquid that wet the glass leads to the capillary rise whereas the formation of convex miniscus leads to the depression in the liquid and shows Capillary Fall.

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