surface tension, property of a liquid surface displayed by its acting as if it were a stretched elastic membrane. This phenomenon can be observed in the nearly spherical shape of small drops of liquids and of soap bubbles. Because of this property, certain insects can stand on the surface of water.
What is the definition of surface tension in physics?
“Surface tension is the tension of the surface film of a liquid caused by the attraction of the particles in the surface layer by the bulk of the liquid, which tends to minimise surface area”.
What is surface tension in 12th physics?
Surface tension is defined as force per unit length acting perpendicular to the tangential line on the surface. It is due to imbalanced attractive forces acting downwards and tends to reduce the surface area of a liquid to minimum.
What is surface tension in physics and its applications?
The surface tension of a liquid is mainly a force that mainly acts to reduce the surface area of a liquid. The directed contracting force which attracts the molecules at the surface of a liquid towards the interior of the liquid is surface tension.
What is surface tension write its unit and dimension?
Solution : The surface tension of a liquid is defined as the energy per unit area of the surface of a liquid
`T = (F)/(l)`
The SI unit and dimensions of T are `N m^(-1)` and `MT^(-2)`, respectively. Answer.
What is surface tension and what is cause?
The surface tension arises due to cohesive interactions between the molecules in the liquid. At the bulk of the liquid, the molecules have neighboring molecules on each side. Molecules are pulling each other equally in all directions causing a net force of zero.
What is the symbol for surface tension?
As a measure of work per unit area or force per wetted length, surface tension has the unit mN/m and is designated by the symbol ;σ (lower case sigma).
Why is surface tension important?
Surface tension determines the efficiency of detergent formulation. The high surface tension of water makes it a relatively poor cleaning detergent. By increasing the temperature of water (as is often done when washing clothes or dishes), the cleaning efficiency increases slightly as surface tension decreases.
What factors affect surface tension?
Surface tension is caused by the effects of intermolecular forces at the interface. Surface tension depends on the nature of the liquid, the surrounding environment and temperature. Liquids where molecules have large attractive intermolecular force will have a large surface tension.
What are the examples of surface tension?
- A Drop of Liquid.
- Soaps and Detergents.
- Washing with Hot Water.
- Clinical Test for Jaundice.
- Water Striders.
- Capillary Action.
- Formation of a Meniscus.
What is the SI unit of surface energy?
The SI unit of Surface Energy is N/m.
What are the two applications of surface tension?
Applications of Surface tension in daily life are: (i) The surface tension of antiseptic ointments is low which make them to spread over the wound. (ii) Adding detergent in water decreases the surface tension of water and enhances the cleaning action of water and detergent both.
What are the three application of surface tension?
1) Walking of insects on water… Small insects can easily walk on water because their weight is not enough to penetrate the surface of liquid or water…. 2) Rounding of bubbles… The surface tension of water provides the necessary wall tension for the formation of bubbles with respect to water….
What is surface tension in Physics for Class 11?
Surface tension is the property of any liquid by virtue of which tries to minimize its free surface area. Surface tension of a liquid is measured as the force acting per length on an imaginary line drawn tangentially on the free surface the liquid. Surface tension S = Force/Length = F/l = Work done/Change in area.
What is the origin of surface tension?
The surface tension of a liquid results from an imbalance of intermolecular attractive forces, the cohesive forces between molecules: A molecule in the bulk liquid experiences cohesive forces with other molecules in all directions. A molecule at the surface of a liquid experiences only net inward cohesive forces.
How do you calculate surface tension?
Surface tension is given by the equation S = (ρhga/2) where S is the surface tension, ρ (or rho) is the density of the liquid you are measuring, h is the height the liquid rises in the tube, g is the acceleration due to gravity acting on the liquid (9.8 m/s2) and a is the radius of the capillary tube.
What is length in surface tension?
The surface tension of the soap film γ pulls on the wire so it produces a force F on it where F is given by: F=2γℓ with ℓ being the length of the wire (the factor of two is because a soap film has two surfaces and each surface pulls on the wire). This is why the surface tension is a force per unit length.
What is high surface tension?
Liquids with high surface tension exhibit significant resistance to penetration compared to the resistance experienced in the bulk of the liquid. Liquids with low surface tension, however, have less of a difference between the tension on the surface and in the rest of the liquid.
What is the conclusion of surface tension?
Answer: Surface tension has been well- explained by the molecular theory of matter. According to this theory, cohesive forces among liquid molecules are responsible for the phenomenon of surface tension. The molecules well inside the liquid are attracted equally in all directions by the other molecules.
What if there is no surface tension?
And, of course, water droplets (rain) and fog condensing as droplets on surfaces are a function of water’s surface tension. Without this property, water would be a slimy coating and cells would not have shape.
Does temperature affect surface tension?
Effect of Temperature on Surface Tension The surface tension of liquids generally decreases with increase of temperature and becomes zero at critical temperature (when meniscus between the liquid and the vapour disappears).
How can we reduce surface tension?
Adding a surfactant to a coating or detergent lowers the surface tension of the liquid so it will flow more, covering the entirety of the surface.
Does surface tension depend on pressure?
Surface Tension of a liquid depends upon Atmospheric pressure, the nature of liquid and its temperature.
How is surface tension used in everyday life?
The effects of surface tension are of central importance in many everyday phenomena: it causes small droplets of rain to stick to your windows, creates bubbles when you add detergent in your sink, and propels water-striding insects on the surface of ponds.
What is meant by surface tension of a liquid?
: the attractive force exerted upon the surface molecules of a liquid by the molecules beneath that tends to draw the surface molecules into the bulk of the liquid and makes the liquid assume the shape having the least surface area.