Question

In a capillary tube, 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,

Rise of water in capillary tube, h = 1.2 mm

Using Ascent formula

`"h" = (2"T""cos"theta)/("r"ρ"g") ⇒ "h" ∝ 1/"r"`

∴ `"h"_1/"h"_2 = "r"_2/"r"_1 ⇒ "h"_2 = "h"_1  "r"_2/"r"_1`

⇒ `"h"_2 = 1.2  "mm" xx "r"/("r"//2) = 2.4  "mm"`