Question

Numerical Problems
35. 2074 Supp. Q.No. 9o Angle of contact of mercury with glass 5-
135º. A narrow tube of glass having diameter 2mm is dipped
in a beaker containing mercury. By what height does the
mercury go down in the tube relative to the level of mercury
outside?​

Answer 1

Answer:

Hi

Here is your answer,

Given , angle of contact (θ) = 140°

Radius of tube (r) = 1 mm = 10⁻³ m

Surface tension (S) = 0.465 N/m

Density of mercury (ρ) = 13.6 × 10³ kg/m³

Height of liquid rise or fall due to surface tension (h)

= 2S cos θ/rρg = 2 × 0.465 × cos 140°/1 × 10⁻³ × 13.6 × 10³ × 9.8

= 2 × 0.465 × (- 0.7660) / 10⁻³ × 13.6 × 10³ × 9.8

= - 5.34 mm

Hence, the mercury level will depressed by 5.34 mm.