Draw the ray diagram in your answer book and show the formation of image of object AB with suitable rays. Mention the position and nature of image.

An object 2cm tall is placed on the axis of a convex lens of focal length 5cm at a distance of 10m from the optical centre of the lens. Find the nature, position and size of the image formed. Which case of image formation by convex lenses is illustrated by this example?

The filament of a lamp is 80cm from a screen and a converging lens forms an image of it on a screen, magnified three times. Find the distance of the lens from the filament and the focal length of the lens.

An object of size 7.0 cm is placed at 27 cm in front of a concave mirror of focal length 18 cm. At what distance from the mirror should a screen be placed, so that a sharp focussed image can be obtained? Find the size and the nature of the image.

The magnification of an image formed by a lens is -1. If the distance of the image from the optical centre of the lens is 25 cm, where is the object placed? Find the nature and focal length of the lens. If the object is displaced 15 cm towards the optical centre of the lens, where would the image be formed? Draw a ray diagram to justify your answer.

Two lenses A and B have focal lengths of +20cm and, -10cm, respectively.

1. What is the nature of lens A and lens B?
2. What is the power of lens A and lens B?
3. What is the power of combination if lenses A and B are held close together?

A converging lens of focal length 5cm is placed at a distance of 20cm 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 100cm from each of the above lenses A and Calculate:

1. Image distance, and
2. Magnification, in each of the two cases.

How far should an object be placed from a convex lens of focal length 20 cm to obtain its image at a distance of 30 cm from the lens? What will be the height of the image if the object is 6 cm tall?

The image of a candle flame formed by a lens is obtained on a screen placed on the other side of the lens. If the image is three times the size of the flame and the distance between lens and image is 80cm, at what distance should the candle be placed from the lens? What is the nature of the image at a distance of 80cm and the lens?