Q: Do protons inside nucleus attract each other? If yes by which force(s)?

A:

Yes, protons inside the nucleus do attract each other. This attraction is due to the strong nuclear force, also known as the strong interaction.

The strong nuclear force is one of the four fundamental forces of nature, along with gravity, electromagnetism, and the weak nuclear force. It is responsible for holding together the protons and neutrons in the nucleus of an atom.

The strong nuclear force is a very powerful force, but it only acts over very short distances, typically within the size of the atomic nucleus. It is also a short-range force, meaning that it becomes weaker as the distance between particles increases.

In the nucleus, the strong nuclear force overcomes the electromagnetic repulsion between the positively charged protons, allowing them to stay together. The number of protons and neutrons in the nucleus determines the strength of the strong nuclear force and, thus, the stability of the nucleus.

Protons also attract each other through gravitational force but this force is too small to have any noticeable effect.