Question

If the length of the free surface of the liquid is doubled, what happens to the surface tension acting on it?

• A. It gets doubled.
• B. It gets quadrupled.
• C. It remains the same.
• D. None of these.

Answer 1

The correct option is C It remains the same.

Surface tension $\left(T\right)$ is a property of interface between two materials i.e liquid and air, hence it will depend only on the characteristic properties (viscosity, density) of the liquid and air involved. It can be altered by altering the temperature or adding impurities like salt, detergent, etc.

$\Rightarrow$Surface tension has been defined as magnitude of tangential force acting on the free surface of liquid per unit length.

$\therefore$ Surface tension will remain same, irrespective of the length of free surface of liquid.