Physics Class 11 Chapter 1. Physical World | Page 8

A few fundamental forces are :
1 . Gravitational Force : It is the force of mutual attraction between any two objects by virtue of their masses . It is a universal force as every object experiences this force due to every other object in the universe .
2 . Electromagnetic Force : It is the force between charged particles . Charges at rest have electric attraction ( between unlike charges ) and repulsion ( between like charges ). Charges in motion produce magnetic force . Together they are called Electromagnetic Force .
3 . Strong Nuclear Force : It is the attractive force between protons and neutrons in a nucleus . It is charge-independent and acts equally between a proton and a proton , a neutron and a neutron , and a proton and a neutron . Recent discoveries show that protons and neutrons are built of elementary particles , quarks .