A coin is placed at a focal point of a converging lens. Is an image formed? If yes, is it real or virtual , erect or inverted, larger or smaller than the object?

Answer 1

Yes, an image will be formed.
The image will be formed at infinity. Because rays after refraction become parallel.
Some books say that image will not be formed if object is placed at focal point.. but image will form but at infinity.
You can understand this better by the example of a telescope.