FORCE ON THE PARTICLE: For a mass m to have acceleration, a force given by F = ma is always required. In uniform circular motion, acceleration is of value v2/t and is directed tends to centre. As a force of magnitude mv2/r is required to keep a particle in circular motion. This force is known as the centripetal force. After studying the given examples, you should carefully notice that the centripetal force is not an extra force on an object. Whatever force is responsible for circular motion changes into the centripetal force.
When a satellite moves around the earth, the gravitational attraction of earth behaves such as the centripetal force for the circular motion of the satellite; when an electron moves around the nucleus in an atom. The electrostatic attraction of nucleus behaves such as the centripetal force for the electron's circular motion. In case of a conical pendulum, T sinΘ changes into the centripetal force.