MHT CET202012 Oct 2020Evening ShiftPhysicsMechanical Properties of FluidsActual
Under isothermal conditions, two soap bubbles of radii ' r₁ ' and ' r₂ ' coalesce to form a big drop. The radius of the big drop is
Options
- A(r₁-r₂ )^ 1 2
- B(r₁+r₂ )^ 1 2
- C(r₁²+r₂² )^ 1 2
- D(r₁²-r₂² )^ 1 2
Correct answer
C. (r₁²+r₂² )^ 1 2
Step-by-step solution
Under isothermal conditions the surface tension remains constant. If r is the radius of the digger drop, then Final surface energy = Initial surface energy 8 r² T=8 r₁² T+8 r₂² T r²=r₁²+r₂² r= (r₁²+r₂² )^ 1 2