Question

Find the surface energy of water kept in a cylindrical vessel of radius 6 cm. Surface tension of water = 0.075 J/m²

• A. 6.5 × 10^-4 J
• B. 8.5 × 10^-3 J
• C. 8.5 × 10^-5 J
• D. 8.5 × 10^-4 J

Answer 1

The correct option is D

8.5 × 10^-4 J

you know,
S=$\frac{V}{A}$
S = Surface tension of the liquid
V = Surface energy
A = Surface Area
Given, r = 6 cm
$A=\pi r2=\pi {\left(\frac{6}{100}\right)}^2{m}^2$
$S=0.075\frac{J}{m^2}$
$V=S\times A=0.075\times \pi \times {\left(\frac{6}{100}\right)}^{2}J$
$V=8.5\times {10}^{-4}\left(approx\right)$