Capillary action of a liquid will take place only when

  1. atmospheric pressure is zero
  2. adhesive forces are greater than the cohesive forces

  3. liquid pressure is equal to atmospheric pressure
  4. none of the above

Answer (Detailed Solution Below)

Option 2 :

adhesive forces are greater than the cohesive forces

Free
UPSC NDA 01/2025 General Ability Full (GAT) Full Mock Test
150 Qs. 600 Marks 150 Mins

Detailed Solution

Download Solution PDF

The correct answer is option 2) i.e. adhesive forces are greater than the cohesive forces

CONCEPT:

  • Capillary action: Capillary action is the movement of a liquid along the surface of a solid due to the attraction of molecules of the liquid to the molecules of the solid.
    • For capillary action to take place, the force between the liquid and solid must be greater than the intermolecular forces of the liquid.
    • The force between two different types of molecules are called adhesive forces and the forces within the same type of molecules are called cohesive forces.

EXPLANATION:

  • Capillary action occurs only when the liquid can move along the surface of another solid. This requires adhesive forces between the liquid and solid.
  • If the cohesive forces within the liquid were greater, the surface tension of the liquid increases and it will try to occupy a lesser surface area possible.
  • Hence, adhesive forces must be greater than the cohesive forces for capillary action to take place.

Latest NDA Updates

Last updated on Jul 8, 2025

->UPSC NDA Application Correction Window is open from 7th July to 9th July 2025.

->UPSC had extended the UPSC NDA 2 Registration Date till 20th June 2025.

-> A total of 406 vacancies have been announced for NDA 2 Exam 2025.

->The NDA exam date 2025 has been announced. The written examination will be held on 14th September 2025.

-> The selection process for the NDA exam includes a Written Exam and SSB Interview.

-> Candidates who get successful selection under UPSC NDA will get a salary range between Rs. 15,600 to Rs. 39,100. 

-> Candidates must go through the NDA previous year question paper. Attempting the NDA mock test is also essential. 

More Fluids Questions

Hot Links: teen patti neta teen patti joy mod apk teen patti bliss teen patti royal