I uploaded a picture to my timeline and set the privacy to "Friends". My friends received notifications. But now I have changed the privacy of the image to public. Will my friends get new notifications or what will happen?
My friends received notifications.
This notification was not about your privacy, it must be a notification about that you have added new photo. So when you change your privacy from Friends to Public, your friends will not get notify about this but now everyone on Facebook (whom you have not blocked) will able to see your this pic as you have set audience public.