Pick out the wrong statement (s) .
(i) Vapour pressure of a liquid is the measure of the strength of intermolecular attractive forces.
(ii) Surface tension of a liquid acts perpendicular to the surface of the liquid.
(iii) Vapour pressure of all liquids is same at their freezing points.
(iv) Liquids with stronger intermolecular attractive forces are more viscous than those with weaker intermolecular force.
- (ii), (iii) and (iv)
- (ii) and (iii)
- (i), (ii) and (iii)
- (iii) only
The Correct Option is D
Solution and Explanation
Top Questions on Surface Tension
- A balloon is made of a material of surface tension S and has a small outlet. It is filled with air of density \( \rho \). Initially the balloon is a sphere of radius R. When the gas is allowed to flow out slowly at a constant rate, its radius shrinks as \( r(t) \). Assume that the pressure inside the balloon is \( P(r) \) and is more than the outside pressure (\( P_0 \)) by an amount proportional to the surface tension and inversely proportional to the radius. The balloon bursts when its radius reaches \( r_0 \). Then the speed of gas coming out of the balloon at \( r = R \) is :
- NEET (UG) - 2025
- Physics
- Surface Tension
- When the angle of contact between a solid and a liquid is \( 90^\circ \), then
- UPCATET - 2025
- Physics
- Surface Tension
- If two soap bubbles A and B of radii \(r_1\) and \(r_2\) respectively are kept in vaccum at constant temperature, then the ratio of masses of air inside the bubbles A and B is
- AP EAPCET - 2025
- Physics
- Surface Tension
- A wire of length 20 cm is placed horizontally on the surface of water and is gently pulled up with a force of $1.456 \times 10^{-2}\, N$ to keep the wire in equilibrium. The surface tension of water is
- AP EAPCET - 2025
- Physics
- Surface Tension
Consider a water tank shown in the figure. It has one wall at \(x = L\) and can be taken to be very wide in the z direction. When filled with a liquid of surface tension \(S\) and density \( \rho \), the liquid surface makes angle \( \theta_0 \) (\( \theta_0 < < 1 \)) with the x-axis at \(x = L\). If \(y(x)\) is the height of the surface then the equation for \(y(x)\) is: (take \(g\) as the acceleration due to gravity)
- NEET (UG) - 2025
- Physics
- Surface Tension
Concepts Used:
Surface Tension
The amount of energy required to increase the liquid's surface area by one unit area is known as surface tension. In other words, it is a property of the liquid surface to resist force.
Surface tension is defined as,
The ratio of the surface force F to the length L along which the force acts.
Mathematically, the surface tension formula can be expressed as follows:
T=F/L
Where,
- F is the force per unit length
- L is the length in which force act
- T is the surface tension of the liquid
Read More: Detergents and Surface Tension
Factors affecting surface tension:
- Impurities: The surface tension decreases with the addition of impurities.
- Surfactants: Adding surfactants in liquids lowers the tension of water making it interrupt aside or get susceptible.
- Temperature: The surface tension of a liquid reduces as the temperature rises.
The Unit of Surface Tension:
The SI unit of Surface Tension is Newton per Meter or N/m.