Question

The amount of work done in blowing a soap bubble such that its diameter increases from d to D is (T= surface tension of the solution)

• A.
• B.
• C.
• D.

Answer 1

The correct option is D

$W=T\times 8\pi (r_2^2-r_1^2)=T\times 8\pi ⟮\frac{D^2}{4}-\frac{d^2}{4}⟯$

$=2\pi (D^2-d^2)T$