Question

A tube of insufficient length is immersed in water (surface tension $=0.07N/m$) with $1cm$ of it projecting vertically upwards outside the water, What is the radius of meniscus? Radius of tube $=1mm$

Answer 1

$h=\frac{2T}{R\rho g}$ ($R=$ radius of meniscus at the top)
$\therefore$ $R=\frac{2T}{h\rho g}=\frac{2\times 0.07}{\left({10}^{-2}\right)\left({10}^3\right)\left(10\right)}$
$=1.4\times {10}^{-3}$ m
$=1.4$ mm