Q 11-09-006NEETNEET 2023Top questionMedium
The amount of energy required to form a soap bubble of radius $2$ cm from a soap solution is nearly : (surface tension of soap solution $= 0.03\ \text{N m}^{-1}$)
Answer: (C) $3.01 \times 10^{-4}$ J
Concept. A soap bubble has two surfaces: $W = S \times 2 \times 4\pi r^2$.
Step 1. Substitute.
$$W = 0.03 \times 8 \times 3.14 \times (0.02)^2 \approx 3.01 \times 10^{-4}\ \text{J}$$
Answer. $3.01 \times 10^{-4}$ J (Option C).
Solution by Sreeraj P, M.Sc Physics