Explain why, a real image can be projected on a screen but a virtual image cannot.

Identify the device used as a spherical mirror or lens in following cases, when the image formed is virtual and erect in each case.Object is placed between infinity and device, image formed is diminished and between focus and optical centre on the same side as that of the object.

List four properties of the image formed by a plane mirror.

An object of height 2.5cm is placed at a distance of 15cm from the optical centre ‘O' of a convex lens of focal length 10cm. Draw a ray diagram to find the position and size of the image formed. Mark optical centre ‘O', principal focus F and height of the image on the diagram.

An object of height 4.0cm is placed at a distance of 30cm from the optical centre ‘O’ of a convex lens of focal length 20cm. Draw a ray diagram to find the position and size of the image formed. Mark optical centre ‘O’ and principal focus ‘F’ on the diagram. Also find the approximate ratio of size of the image to the size of the object.

Why does a driver prefer to use a convex mirror as a rear-view mirror in a vehicle?

Draw a labelled ray diagram to show the formation of image of an object by a convex mirror. Mark clearly the pole, focus and centre of curvature on the diagram.

It is desired to obtain an erect image of an object, using concave mirror of focal length of 12cm.
Will the image be smaller or larger than the object? Draw ray diagram to show the formation of image in this case.

When an object is placed at a distance of 36cm from a convex lens, an image of the same size as the object is formed. What will be the nature of image formed when the object is placed at a distance of:

1. 10cm from the lens?
2. 20cm from the lens?

Describe the nature of image formed when the object is placed at a distance of 20cm from a concave mirror of focal length 10cm.