It is called the hub.
The Indian flag has a ashoka chakra [a wheel] in the center of it symbolizing the circle of life and death.
No. Every circle on the sphere whose center is also the center of the sphere is a great circle. If the circle's center is not also the center of the sphere, then the circle is a small circle.
No it's made by the circle that how they get the circle not the center.
A RADIUS connects the center of a circle to any point on the circle.
This circle is called the center circle.
The cord of a circle that contains the center of that circle is a diameter of that circle.
A chord of a circle that contains the center of the circle is called the diameter.
The line from the center of a circle to a point on the circle is the radius.
The point from which the circle is drawn IS the center.