A container is partially filled with a liquid of density `rho_2` A capillary tube of radius r is vertically inserted in this liquid. Now another liquid of density `rho_1(rho_1ltrho_2)` is slowly poured in the container to a height h as shown. There is only denser liquid in the capillary tube. The rise of denser liquid in the capillary tube is also `h`. Assuming zero contact angle, the surface tension of heavier liquid is

Options

A. `rrho_2gh`
B. `2pirrho_2gh`
C. `(r )/(2)(rho_2-rho_1)gh`
D. `2pir(rho_2-rho_1)gh`

Answer

C

Explanation

`P_0+rho_1gh-rho_2gh+(2T)/(r )=P_0`
`impliesT=(r )/(2)(rho_2-rho_1)gh`