Question

The surface tension of a soap solution is T. The work done in blowing a soap bubble of diameter d to that of a diameter 2d is ______.

Options

• 4πd²T

• 2πd²T

• 8πd²T

• 6πd²T

Answer 1

The surface tension of a soap solution is T. The work done in blowing a soap bubble of diameter d to that of a diameter 2d is 6πd²T.

Explanation:

Change in surface area = `2 xx 4pi[((2d)/2)^2 - (d/2)^2]`

= 2π × 3d²

∴ Work done in blowing a soap bubble,

W = Surface tension × Change in area

= T × 2π × 3d² = 6πd²T