Pure water rises through a height h in a capillary tube of internal radius (r ). If T is the S.T of water , then the pressure diference between water level in the container and the lowest point of the concave meniscus is

Options

A. `T/r`
B. `r/T`
C. `(2T)/r`
D. `r/(2T)`

Answer

C

Explanation

For capillary rise ,` rhrhog = 2 T cos theta`
and the pressure difference =` h rho g `
` :. dp= hrhog=(2Tcos theta)/r`
For water `theta = 0^(@) , cos theta = 1 " " :. dp=(2T)/r`