Question

What is the unit of surface tension?
1. Newton x meter
2. Newton / meter
3. Joule
4. Newton 

Answer 1

Correct Answer - Option 2 : Newton / meter

CONCEPT:

• Surface tension: Surface tension is the property by virtue of which liquid tires to minimize its free surface area.
  • In a spherical shape the surface area is minimum and for this reason, the raindrops are spherical.
  • Surface tension is measured as the force acting per unit length of an imaginary line drawn on the liquid surface.

\(Surface\;tension = \frac{{Force}}{{length}}\)

EXPLANATION:

• The SI unit of force is Newton (N).
• The SI unit of length is meter (m).
• So the SI unit of surface tension is Newton/meter (N/m). Hence option 2 is correct.