Question

Soap solution bubble having radius `1/sqrtπ` cm is expanded to a bubble of radius `4/sqrtπ`. If the surface tension of soap solution is 30 dyne/cm, then the work done is ______.

Options

• 180 erg

• 3600 erg

• 7200 erg

• 960 erg

Answer 1

Soap solution bubble having radius `1/sqrtπ` cm is expanded to a bubble of radius `4/sqrtπ`. If the surface tension of soap solution is 30 dyne/cm, then the work done is 3600 erg.

Explanation:

Work done

`= "T"xx[4πxx(4/sqrtπ)^2-4πxx(1/sqrtπ)^2]xx2`

`=30 xx 60xx 2=3600` erg