Question

An open capillary tube is lowered in a vessel with mercury. The difference between the levels of the mercury in the vessel and in the capillary tube is $Δh= \, \text{4.6} \, mm$ . The radius of curvature of the mercury meniscus in the capillary tube will be (surface tension of mercury is $\text{0.46} \, N \, m^{- 1}$ of mercury is $\text{13.6} \, g \, cm^{- 3}$ )

• A. $\frac{1}{340}m$
• B. $\frac{1}{680}m$
• C. $\frac{1}{1020}m$
• D. information is insufficient

Answer 1

Answer: (B)

$Δh=\frac{2 Scos \theta }{rρg}=\frac{2 S}{Rρg}$
$\Rightarrow R=\frac{2 S}{Δhρg}$