NEETPhysicsMechanical Properties of Fluids
Match List I with List II regarding the excess force required to detach various objects from a liquid surface of surface tension T . List I (Object) List II (Excess force) A. Circular disc of radius r I. 8aT B. Circular ring of radius r II. 4aT C. Square plate of side a III. 4 rT D. Square frame of side a IV. 2 rT Choose the correct answer from the options given below:
Options
- AA-III, B-IV, C-II, D-I
- BA-IV, B-III, C-II, D-I
- CA-IV, B-III, C-I, D-II
- DA-III, B-IV, C-I, D-II
Correct answer
B. A-IV, B-III, C-II, D-I
Step-by-step solution
The excess force required to detach an object from a liquid surface is given by F = T L_ eff , where L_ eff is the effective length of the boundary in contact with the liquid. A. Circular disc of radius r : The liquid touches only the outer perimeter. L_ eff = 2 r . Excess force = 2 rT . (Matches IV) B. Circular ring of radius r : The liquid touches both the inner and outer perimeters. L_ eff = 2 r + 2 r = 4 r . Excess force = 4 rT . (Matches III) C. Square plate of side a : The liquid touches only the outer perime