Question

In a capillary tube, the water rises by 1.2 mm. The height of water that will rise in another capillary tube having half the radius of the first is:

Options

• 0.4 mm

• 0.6 mm

• 1.2 mm

• 2.4 mm 

Answer 1

2.4 mm 

Explanation:

Given,

 calculate the rise of water in a capillary tube with h = 1.2 mm.

Using the Ascent formula,

h = `(2"T" cos θ)/"rpg"`

⇒ h α `1/"r"`

∴ `"h"_1/"h"_2 = "r"_2/"r"_1`

⇒ h₂ = h₁ `"r"_2/"r"_1`

⇒ `"h"_2 = 1.2 "mm" xx "r"/("r"//2)`

= 2.4 mm