In capillary rise, if radius, density and surface tension each decrease by 1%, then how much percentage change occurs in height of liquid column?

Solution:

Formula of capillary rise:

h = (2T cosθ) / (rρg)

Therefore:

h ∝ T / (rρ)

Percentage changes:

• Surface tension decreases by 1%
• Radius decreases by 1%
• Density decreases by 1%

Using percentage rule:

Percentage change in h = (-1%) - (-1%) - (-1%)

= -1% +1% +1%

= +1%

Answer: Height of liquid column increases by 1%.