Question

Take a ring of wire and dip it in a soap solution. When the ring is taken out, a soap film. Now, ** a * inside the loop. The thread is radially pulled by the film surface outside and it takes a circular shape.

Answer 1

Before the pricking, there were surfaces both inside and outside the thread loop. Surface on both sides pull it equally and the net force is zero. Once the surface inside was punctured, the outside surface pulled the thread to take the circular shape so that area outside the loop becomes minimum.