Why are clothes easily washed by soap or detergent?
(N/A) The addition of soap or detergent to water reduces the angle of contact. Dirt particles are trapped within the fabric fibers. The molecules of detergent are hairpin-shaped,with one end attracted to water (hydrophilic) and the other end attracted to molecules of grease,oil,or wax (hydrophobic/dirt). This structure forms water-oil interfaces,which drastically reduces the surface tension of the water. As a result,the water can penetrate the fabric more effectively and lift the dirt away,allowing clothes to be washed easily.
Conversely,a waterproofing agent is added to fabrics to increase the angle of contact between water and the fibers,preventing water from wetting the material.
Conversely,a waterproofing agent is added to fabrics to increase the angle of contact between water and the fibers,preventing water from wetting the material.
Explore More
Similar Questions
$A$ thin metal disc of radius $r$ floats on water surface and bends the surface downwards along the perimeter,making an angle $\theta$ with the vertical edge of the disc. If the weight of water displaced by the disc is $W$,the weight of the metal disc is [$T =$ surface tension of water].
DifficultMHT CET 2021
View Solution$A$ beaker of radius $15\, cm$ is filled with a liquid of surface tension $0.075\, N/m$. The force across an imaginary diameter on the surface of the liquid is:
Easy
View SolutionHairs of a shaving brush cling together when it is removed from water due to
$A$ wire of length $10 \text{ cm}$ is gently placed horizontally on the surface of water having surface tension of $75 \times 10^{-3} \text{ N/m}$. What force is required to just pull up the wire from the water surface?
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 an angle $\theta_0 \left(\theta_0 \ll 1\right)$ with the $x$-axis at $x=L$. If $y(x)$ is the height of the surface,then the equation for $y(x)$ is:
(Take $\theta(x) \approx \sin \theta(x) \approx \tan \theta(x) = \frac{dy}{dx}$,where $g$ is the acceleration due to gravity.)
(Take $\theta(x) \approx \sin \theta(x) \approx \tan \theta(x) = \frac{dy}{dx}$,where $g$ is the acceleration due to gravity.)
DifficultNEET 2025
View SolutionVedclass Products
For Students
Vedclass Test Series
Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.
Start Free TrialFor Teachers
Exam Paper Generator
Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.
Try FreeFor Institutes
Online Exam Module
Live online exams with unlimited students, 360° analytics & white-label branding.
See Demo