If work `W` is done in blowing a bubble of radius `R` from a soap solution. Then the work done is blowing a bubble of radius `2R` from the same solution is

Options

A. 2 W
B. 4W
C. W/4
D. W/2

Answer

B

Explanation

For a soap bubble , we multiply the area by 2 because there are two free surfaces
The work done in blowing a soap bubble of radius R = W ` = 2 (4 pi R^(2))xx T = 8piR^(2)T`
and the work done in making a soap bubble of radius 2R is W' = 2 `[ 4pi (2R)^(2)] xx T = 8piT (4R^(2)) = 4 W `