If a liquid does not wet glass, its angle of contact is
- zero
- acute
- obtuse
- right angle
The Correct Option is C
Solution and Explanation
contact is obtuse.
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 :
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- 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
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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)
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Questions Asked in KCET exam
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You are given a dipole of charge \( +q \) and \( -q \) separated by a distance \( 2l \). A sphere 'A' of radius \( R \) passes through the centre of the dipole as shown below and another sphere 'B' of radius \( 2R \) passes through the charge \( +q \). Then the electric flux through the sphere A is
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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.