Three liquids of densities `rho_(1), rho_(2)` and `rho_(3)` (with `rho_(1) gt rho_(2) gt rho_(3)`), having the same value of surface tension T, rise to the same height in three identical capillaries. The angles of contact `theta_(1), theta_(2)` and `theta_(3)` obey

Options

A. `(pi)/(2) gt theta_(1) gt theta_(2) gt theta_(3) ge 0`
B. `0 le theta_(1) lt theta_(2) lt theta_(3) lt (pi)/(2)`
C. `(pi)/(2) lt theta_(1) lt theta_(2) lt theta_(3) lt pi`
D. `pi gt theta_(1) theta_(2) gt theta_(3) gt (pi)/(2)`

Answer

B

Explanation

`h=(2Tcostheta_(c))/(r rhog)=`same
`costheta_(c) prop rho`
`rho_(1) gt rho_(2) gt rho_(3)`
`costheta_(c_(1)) gt cos theta_(c_(2)) gt cos theta_(c_(3))`
`0 le theta_(c_(1)) lt theta_(c_(2)) lt theta_(c_(3)) lt (pi)/(2)`