Definitions [6]
Define the sphere of influence.
A molecule's sphere of influence is described as an imaginary sphere with the molecule at its centre and the molecular range as its radius.
Define the molecular range.
The maximum distance at which an appreciable intermolecular force of attraction exists between two molecules is known as the molecular range or range of molecular attraction.
Define the angle of contact for a given pair of solid and liquid.
The angle between tangents drawn at the point of contact to the liquid surface and the solid surface inside the liquid is called the angle of contact for a pair of solid and liquid. It is denoted by θ.
Define the surface tension of a liquid.
Surface tension is defined as the force acting on a unit length of an imaginary line drawn on the free surface of the liquid, the direction of the force being perpendicular to the line so drawn and acting parallel to the surface.
Define angle of contact.
When a liquid is in contact with a solid, the angle between the tangent drawn to the free surface of the liquid and the surface of solid at the point of contact measured inside the liquid is called the angle of contact.
Define surface tension.
Surface tension is defined as the force per unit length acting at right angles to an imaginary line drawn on the free surface of the liquid.
Important Questions [35]
- The dimensional formula of surface tension is ______.
- Derive Laplace’s law for spherical membrane of bubble due to surface tension.
- Calculate Surface Tension of Water at 25°C
- Derive an Expression for Excess Pressure Inside a Drop of Liquid.
- Angle of Contact for the Pair of Pure Water with Clean Glass is
- Calculate the Pressure Inside the Raindrop.
- Draw a Neat Labelled Diagram Showing Forces Acting on the Meniscus of Water in a Capillary Tube.
- Define the Angle of Contact.
- Find the Height to Which the Same Water Will Rise in Another Glass Capillary Having Half Area of Cross Section.
- In Which of the Following Substances, Surface Tension Increases with Increase in Temperature ?
- N' Droplets of Equal Size of Radius R Coalesce to Form a Bigger Drop of Radius R. the Energy Liberated is Equal to
- The Surface Tension of Water at 0ºC is 75·5 dyne/em. Find Surface Tension of Water at 25°C.
- Find the Diameter of the Drop in C.G.S. System.
- The Total Free Surface Energy of a Liquid Drop is `Pisqrt2` Times the Surface Tension of the Liquid. Calculate the Diameter of the Drop in S.L. Unit.
- In a Conical Pendulum, a String of Length 120 Cm is Fixed at Rigid Support and Carries a Mass of 150 G at Its Free End. If the Mass is Revolved in a Horizontal Circle of Radius 0.2 M Around a Vertical Axis, Calculate Tension in the String
- A Body Weighs 4.0 Kg-wt on the Surface of the Earth. What Will Be Its Weight on the Surface Of a Plant Whose Mass is 1/8 Th Of the Mass of the Earth and Radius Half (1/2) Of that of the Earth
- Show that the Surface Tension of a Liquid is Numerically Equal to the Surface Energy per Unit Area.
- A Big Drop of Radius R is Formed from 1000 Droplets of Water. the Radius of a Droplet Will Be _______
- State Any Two Characteristics of Angle of Contact
- Calculate the Work Done in Increasing the Radius of a Soap Bubble in Air from 1 Cm to 2 Cm. the Surface Tension of Soap Solution is 30 Dyne/Cm. (π = 3.142)
- When a Sparingly Soluble Substance like Alcohol is Dissolved in Water, Surface Tension of Water
- Define surface tension.
- Eight droplets of water each of radius 0.2 mm coalesce into a single drop. Find the decrease in the surface area.
- The total energy of free surface of a liquid drop is 2π times the surface tension of the liquid. What is the diameter of the drop? (Assume all terms in SI unit).
- Define Surface Tension and Surface Energy.
- Explain the Rise of Liquid in the Capillary on the Basis of Pressure Difference.
- Draw a Neat, Labelled Diagram for a Liquid Surface in Contact with a Solid, When the Angle of Contact is Acute.
- A liquid rises in glass capillary tube upto a height. If another glass capillary tube having radius half that of the earlier tube is immersed in the same Liquid, the rise of liquid in it will be __.
- Two Soap Bubbles Have Radii in the Ratio 4:3. What is the Ratio of Work Done to Blow These Bubbles?
- Calculate the Density of Paraffin Oil
- If two capillary tubes of different diameters are partially dipped in the same liquid vertically, then the rise of liquid ______.
- Draw a Neat Labelled Diagram of Rise of Liquid in Capillary Tube Showing Different Components of Tension (Force).
- Obtain an expression for the rise of a liquid in a capillary tube.
- A Soap Bubble of Radius 12 Cm is Blown. Surface Tension of Soap Solution is 30 Dyne/Cm. Calculate the Work Done in Blowing the Soap Bubble.
- Why a detergent powder is mixed with water to wash clothes?
