The distance between a real object and its real image is 56 cm formed by converging lens, focal length of lens is
A diverging lens, focal length f1=20 cm is separated by 5 cm from a converging mirror, focal length f2=10 cm. Where should an object be placed from the lens so that a real image is formed at the object itself ?
An object is placed at adistance of 5 cm more than the focal length f of a convex lens. Its real image is formed at a distance 3f beyond the focus .The focal length f of thelens is:
The minimum distance between an object and its real image formed by a thin convex lens of focal length f is Kf. Find the value of K.