The surface tension of soap solution is `0.03 N//m` . The work done in blowing to from a soap bublle of surface area `40 cm^(2)`, (in J) , is

Options

A. `1.2 xx 10 ^(-4)`
B. `2.4 xx 10 ^(-4)`
C. `12xx 10 ^(-4)`
D. `24 xx 10 ^(-4)`

Answer

B

Explanation

In case of soap bubble
`W = T xx 2 xx Delta A`
`= 0. 3 xx 2 xx 40 xx 10 ^(-4) = 2.4 xx 10 ^(-4) J`