A soap bubble of raidus `R` is surrounded by another soap bubble of radius `2R`, as shown. Take surface tension `=S`. Then the pressure inside the smaller soap bubble, in excess of the atmosphere presure will be

Options

A. `(4S)/(R )`
B. `(3S)/(R )`
C. `(6S)/(R )`
D. none of these

Answer

C

Explanation

`P_1=P_0=(4S)/(2R)` ..(i)
`P_2-P_1=(4S)/(R )` .(ii)
From (i) and (ii) `P_2-P_0=(6S)/(R )`