If 3 concave mirrors are cut from a sphere and put in the given set up and if the sun lies on the principle axis of mirror 2 at infinity, then at what position will the images of the sun be formed by three mirrors?
at F2 only.
If the mirror were whole and complete then the image of an object at infinity will be at the focus (f).
Now if some parts of the mirror are blocked to form 3 mirrors as shown in the question, then the position of the image will not be affected. But the brightness of the image reduces (due to missing part of mirror)