A small soap bubble of radius 4cm is trapped inside another bubble of radius 6cm without any contact. Let P 2 be the pressure inside the inner bubble and P 0 , the pressure outside the outer bubble. Radius of another bubble with pressure difference P 2 - P 0 between its inside and outside would be:

Step-by-step solution

P 2 − P 1 = 4 T r 1             .... ( 1 ) P 1 − P 0 = 4 T r 2     ..... ( 2 ) adding ( 1 )   &   ( 2 ) P 2 − P 0 = 4 T r 1 + 4 T r 2 P 2 = P 0 + 4 T r 1 + 4 T r 2 P 2 = P 0 + 4 T 6 + 4 T 4 for another bubble of radius r P 2 =   P 0 + 4 T r ⇒       1 r = 1 6 + 1 4 ⇒       r = 2.4   cm