By giving sign-conventions, derive the lens formula relating object distance, image distance and focal length for a thin convex lens. Draw a ray diagram to show the formation of image of an object placed between optical centre and focus of a convex lens.

Draw a ray diagram to show the image formation by a concave mirror, when the object is kept between its focus and the pole.

The graph drawn with object distance along abbscissa and image distance as ordinate for a convex lens is

An object is placed at a distance of f//2 from a convex lens .The image will be

The graph between object distance u and image distance v for a lens is given below. The focal length of the lens is. .

A convex lens forms a virtual image of an object. What is the position of the object?

A convex lens of focal lenght 20 cm is placed coaxially wih a convex mirror of radius of curvature 20 cm.the two are kept at 15 cm apart.A point object lies 60 cm in front of the convex lens.Draw a ray diagram to show the formation of the image by the combination.Determine the nature and position of the image formed.

The focal length of a convex lens is 30 cm and the size of image is quarter of the object.Them,the object distance is

What is minimum distance between an object and the real image formed by a convex lens?