.Sunday, February 8, 2009 ' 7:53 PM Y
Meniscus, is a curve in the surface of a liquid and is produced in response to the surface of the container or another object. It can be either concave or convex.
A convex meniscus occurs when the molecules have a stronger attraction to each other than to the container.This may be seen between mercury and glass in barometers.Conversely, a concave meniscus occurs when the molecules of the liquid attract those of the container. This can be seen between water and glass.
Capillary action acts on concave menisci to pull the liquid up, and on convex menisci to pull the liquid down. This phenomenon is important in transpirational pull in plants. Honey, water, milk etc. have a lower meniscus. When a tube of a narrow bore, often called a capillary tube, is dipped into a liquid and the liquid “wets” the tube, the liquid surface inside the tube forms a concave meniscus, which is a virtually spherical surface having the same radius, as the inside of the tube. The tube experiences a downward force of magnitude Mercury etc. have an upper convex meniscus.
