1.

Explain the rise of liquid in the capillary on the basis of pressure difference.

Answer» When a capillary tube is dipped in water, the water meniscus inside the tube is concave. The pressure just below the meniscus is less than the pressure just above it by 2T/R, where T is the surface tension of water and R is the radius of curvature of meniscus. The pressure on the surface of water is atmospheric prssure P. The pressure just below the plane surface of water outside the tube is `"P"-("2T"//"R")`. We know that pressure at all points in the same level of water must be the same. Therefore, to make up the deficiency of pressure, 2T/R, below the meniscus, water begins to flow from outside to inside the tube. The rising of water in the capillary takes place.


Discussion

No Comment Found

Related InterviewSolutions