In order to obtain a real image twice the size of the with a convex lens of focal length 15 cm, the object distance should be:

To form an image twice the size of the object, using a convex lens of focal length 20 cm, the object distance must be

Draw a labelled ray diagram for the formation of image by a convex lens of focal length 15 cm when the object is placed at a distance of 25 cm from the lens. Determine the size of the image formed, if size of the object is 4 cm.

Draw a labelled ray diagram for the formation of image by a convex lens of focal length 15 cm when the object is placed at a distance of 25 cm from the lens. Determine the size of the image formed, if size of the object is 4 cm.

A real image is obtained at 30 cm from a convex lens of focal length 7.5 cm .Find the distance of the object from tne lens .

A real image is obtained at 30 cm from a convex lens of focal length 7.5 cm . Find the distance of the object from the lens .

An object 6 cm in size is placed at 50 cm in front of a convex lens of focal length 30 cm. At what distance from the lens should a screen be placed in order to obtain a sharp image of the object? Find the nature and size of the image. Also, draw labelled ray diagram to show the image formation in this case.