Which force is responsible for producing a stable nucleus by opposing the electrostatic force of repulsion between protons

The nucleus is complicated because many phenomena happen inside. You have to consider the numberer of particles, the distance between them and their energy. In general nucleus is strable when the electrostatic force is balanced by the nuclear force between the neutrons and the protons.

It is the areas with lines. this may sound a little confusing, but i hope it !