# CBSE Class 11-Physics: Surface Tension Worksheet: Derivations (For CBSE, ICSE, IAS, NET, NRA 2023)

Get top class preparation for CBSE/Class-8 right from your home: get questions, notes, tests, video lectures and more- for all subjects of CBSE/Class-8.

## Derivations and Definition-Based Problems

Question 1:

Define Surface tension and explain surface tension based on molecular theory.

Question 2:

Define Surface energy. Prove it is numerically equal to surface tension.

Question 3:

Show that a pressure difference exists between two sides of curved liquid surface.

Question 4:

Derive an expression for excess pressure

(a) Inside a liquid drop

(b) Inside a soap bubble.

Question 5:

What do you understand by the term capillarity? Give some examples of capillarity from daily life.

Question 6:

Derive an expression for the rise of liquid in capillary tube and show that the height of the liquid column supported is inversely proportional to the radius of the tube.

## Numerical Based Problems

Question 1:

Calculate the work done in blowing in a soap bubble from radius to . The surface tension of the soap solution is .

Question 2:

The liquid drop of diameter D breaks up into tiny drops. Find the resulting change in energy. Take surface tension of liquid as .

Question 3:

If of work is done in blowing a soap bubble of a radius , what additional work is required to be done to blow it to a radius equal to ?

Question 4:

Soapy water drips from capillary. When the drop breaks away, the diameter of its neck is . The mass of the drop is . Find the surface tension of the soapy water. (Answer:- )

Question 5:

If the number of little droplets of water of surface tension , all of the radius , combine to form a single drop of radius R and the energy released is converted into kinetic energy, find the velocity acquired by the bigger drop.

Question 6:

What should be the pressure inside a small air bubble of radius, situated just below the surface? Surface tension of water and atmospheric pressure

Question 7:

Two soap bubbles have radii in ratio . Compare the excess pressure of liquid inside these bubbles. Also compare the works done in blowing these bubbles.

Question 8:

Water rises in a capillary tube to a height of . In another capillary tube whose radius is one-third of it, how much the water will rise?