Question

40. The excess pressure due to surface tension inside
a spherical drop is 6 N/m2. If 27 such drops
coalesce, the excess pressure inside the new drop
is
a) 6 N/m2
b) 18 N/m2
c) 12 N/m² so sild) 2 N/m2
5​

Answer 1

Given:Pin−Port=r4T=6 units

If  eight  such  drops  coalesce

⇒8(34πr3)=34πr13

r1=2r

∴ excess Pressure :Pin−Port=r14T=2r4T=26 =3 units