In Fig. a convex, lens L is placed at a distance of 36 cm from a screen. If a point-source P is placed at 56 cm from the screen then a circular spot of light of diameter equal to the diameter of the lens is formed. Show the image formation by a ray diagram. Calculate upto what distance the source be displaced so that its clear image can be formed on the screen.

A convex lens is placed at a distance of 40 cm from a screen. A point source is placed at a distance of 60 cm from the screen on the same side of the lens. At this position of point-source, a circular spot of light of diameter equal to the lens is formed. Show the formation of image by a ray diagram. Up to what distance the source be displaced so that its clear image can be formed on the screen?

A converging lens of focal length 5 cm is placed at a distance of 20 cm from a screen. How far from the lens should an object be placed so as to form its real image on the screen?

An object is placed at a distance of 80 cm from a screen. Where should a convex lens of focal length 15 cm be placed from object such that a real image of object is formed?

An object is placed at a distance of 20 cm from a convex lens of focal length 10 cm . The image is formed on the other side of the lens at a distance

A luminous object is placed at a distance of 40 cm from a converging lens of focal length 25 cm. The image obtained in the screen is

An illuminated object is placed at a distance of 20 cm from a converging lens of focal length 15 cm. The image obtained on the screen is:

A 1 cm high object is placed at a distance of 2f from a convex lens. What is the height of the image formed?