The plane faces of two identical planoconvex lenses each having focal length of `40 cm` are pressed against each other to form a usual convex lens. The distance from this lens, at which an object must be placed to obtain a real, inverted image with magnification one is

The plane faces of two indentical plano-convex lens, each having focal length of 80 cm, are placed against each other to form a usual convex lens. The distance from this lens at which an object must be placed to obtain a real, inverted image with magnification one is :

The plane faces fo two identical plano-convex lenses each having a focal length of 50 cm are placed against each other to form a usual biconvex lens. The distance from this lens combination at which an object must be placed to obtain a real, inverted image which has the same size as the object is

The place faces of two identical plano-convex lenses, each with focal length f are pressed against each other using an optical glue to from a usual convex lens .The distance from the optical centre at which an object must be placed to obtain the image same as the size of the object is

The place faces of two identical plano-convex lenses, each with focal length f are pressed against each other using an optical glue to from a usual convex lens .The distance from the optical centre at which an object must be placed to obtain the image same as the size of the object is

At what distance an object must be placed from a lens of focal length 15 cm to get an inverted image of unit magnification ?

A lens with a focal length of 25 cm produces real image of an object at a distance of 50 cm from the lens. At what distance the object placed from the lens?

A convex lens of focal length 16 cm forms a real image double the size of the object. The image distance of the object from the lens is

A plano-convex lens of focal length 30 cm has its plane surface silvered. An object is placed 40 cm from the lens on the convex side. The distance of the image from the lens is