What optical instrument can best be constructed with converging lenses of focal lengths 50cm and 5cm?

Answer Details

The optical instrument that can best be constructed with converging lenses of focal lengths 50cm and 5cm is an astronomical telescope. An astronomical telescope is used to observe distant objects in space, such as stars and planets. It uses two converging lenses - an objective lens and an eyepiece - to produce an enlarged image of the object being observed. The objective lens has a longer focal length, while the eyepiece has a shorter focal length. The objective lens collects and focuses the light from the object, forming a real image that is then magnified by the eyepiece. In this case, the 50cm focal length lens would be used as the objective lens, and the 5cm focal length lens would be used as the eyepiece.