[" A concave lens of focal length "20cm" product an "],[" image half in size of the real object.The distance of the "],[" real object is "]

A concave lens of focal length 20 cm product an image half in size of the real object. The distance of the real object is

A concave lens of focal length 20 cm product an image half in size of the real object. The distance of the real object is

A concave lens of focal length f produces an image (1//n) times the size of the object. The distance of the object from the lens is :

A concave mirror of focal length f produces a real image n times the size of the object. The distance of the object from the mirror is

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

A concave lens of focal length (1)/(3)m forms a real, inverted image twice in size of the object. The distance of the object from the lens is

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