On the surface of water we drop three pieces of thread which are linked to each other as shown in the figure. The threads do not sink but remain on the water surface. (ℓ2 = ℓ3 = π cm, ℓ1 = 2π cm) Now we drop a detergent at point A which decreases the surface tension in that region by a factor of 3.5 without changing the surface tension in other regions. In the next step, we drop the same detergent at point B. The coefficient of surface tension of water is 0.07 N/m. It changes surface tension in region B without changing it in other regions.

On the surface of water we drop three pieces of thread which are linked to each other as shown in the figure. The threads do not sink but remain on the water surface. (ℓ₂ = ℓ₃ = π cm, ℓ₁ = 2π cm)

Now we drop a detergent at point A which decreases the surface tension in that region by a factor of 3.5 without changing the surface tension in other regions. In the next step, we drop the same detergent at point B. The coefficient of surface tension of water is 0.07 N/m. It changes surface tension in region B without changing it in other regions.