Download App

Surface Tension — JEE physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 ScienceJEE physicsSurface Tension1 Mark
Question
Assertion : The impurities always decrease the surface tension of a liquid.
Reason : The change in surface tension of the liquid depends upon the degree of contamination of the impurity.
✓

Answer

(e) The presence of impurities either on the liquid surface or dissolved in it, considerably affect the force of surface tension, depending upon the degree of contamination. A highly soluble substance like sodium chloride when dissolved in water increase the surface tension. But the sparing soluble or substance like phenol when dissolved in water reduces the surface tension of water.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "Assertion & Reason" from Surface Tension→Surface Tension — all question types→JEE physics STD 12 Science question papers→CBSE Board STD 12 Science question papers→CBSE Board question paper generator→

Similar questions

Assertion : When a body is dropped or thrown horizontally from the same height, it would reach the ground at the same time.
Reason : Horizontal velocity has no effect on the vertical direction.
→
Assertion : The rate of change of total momentum of a many particle system is proportional to the sum of the internal forces of the system.
Reason : Internal forces can change the kinetic energy but not the momentum of the system.
→
Assertion : The images formed by total internal reflections are much brighter than those formed by mirrors or lenses.
Reason : There is no loss of intensity in total internal reflection.
→
Assertion : Air quickly leaking out of a balloon becomes coolers
Reason : The leaking air undergoes adiabatic expansion.
→
Assertion : The rate of change of total momentum of a many particle system is proportional to the sum of the internal forces of the system.
Reason : Internal forces can change the kinetic energy but not the momentum of the system.
→
Assertion : A large force is required to draw apart normally two glass plates enclosing a thin water film.
Reason : Water works as glue and sticks two glass plates.
→
Assertion : On a rainy day, it is difficult to drive a car or bus at high speed.
Reason : The value of coefficient of friction is lowered due to wetting of the surface.
→
Assertion : The equation of motion can be applied only if acceleration is along the direction of velocity and is constant.
Reason : If the acceleration of a body is constant then its motion is known as uniform motion.
→
Assertion : Specific heat of a body is always greater than its thermal capacity.
Reason : Thermal capacity is the required for raising temperature of unit mass of the body through unit degree.
→
Assertion : Consider motion for a mass spring system under gravity, motion of $M$ is not a simple harmonic motion unless $M g$ is negligibly small.
Reason : For simple harmonic motion acceleration must be proportional to displacement and is directed towards the mean position

Image

→