An open cappillary tube contains a drop of water. The internal diameter of the capillary tube is `1mm`. Daternube tge radii if curvature of the upper and lower meniscuses in each case. Consider the wetting to be complete. Surface tension of water `= 0.073 N//m`. `(g = 9.8 m//s^(2))`
When the tube is in its vertical position, the drop froms a column witha length of `2.98 cm`.

Options

A. `0.5 mm, 1.52 mm`
B. `0.5 mm, 1.46 mm`
C. `0.5 mm`, lower surface will be flat
D. `0.4 mm, 1.46 mm`

Answer

C

Explanation

As the wetting is complete. So upper meniscus radius will be
same as radius of capillry in all cases. `r_(4) = (r_("capillary"))/(2) = 0.5 mm`.
Now `(a)`
`Fs = T xx 2 pirl`.
so balancing forces in vertical direction.
`rho xx (pir_(c)^(2) xx h)xx g = T xx 2pir_(1) + T xx 2pir_(c)`.
get `r_(1) = (rhohgr_(c)^(2))/(2T) - r_(c)`