Answer
Make a small circle and from the Appearance Panel select the fill and from the menu Effect → Distort & Transform → Transform:
- Go to menu Object → Expand Appearance
- Press R to activate the Rotate Tool and holding
Alt click at the small circle center - At the pop up window type
360/24
then Copy
- Press Cmd + D Mac or Ctrl + D Win to transform again until get the whole object
- Change the colors alternately
Attribution
Source : Link , Question Author : raju , Answer Author : Community