How far from a lamp must a concave mirror of focal length 3 m be placed in order to throw an image on a screen 8 m from the lamp?

A candle is flame 1 cm high is placed at a distance of 1.5 metre from a wall.How far from the wall must a concave mirror be placed ,so that it may form a 2 cmhigh image of the flame on the flame on the same wall?Also find the focal length of the mirror.

An object is placed at a distance of 40 cm from a concave mirror of focal length 15 cm.If the objects is displaced through a distance of 20 cm towards the mirror,by how much distance is the image displaced.

An object of size 5 cm is placed at distance 25 cm in front of a concave mirror of focal length 20 cm. Find the size and nature of image formed ? Also find distance of image from the mirror.

A convex lens of foal length 30 cm and a concave lens of focal length 60 cm are placed in contact.If the object is placed 40 cm away from the combination ,, find the position of the image.

We wish to obtain an erect image of an object, using a concave mirror of focal length 15cm what should be the range of distance of the object from the mirror? What is the nature of the image ? Is the image larger or smaller than object? Draw a ray diagram to show the image formation in this case.

The size of the image of an object,which is at infinity, as formed by a convex lens of focal length 30 cm is 2 cm. If a concave lens of focal length 20 cm is placed between the convex lens and the image at a distance of 26 cm from the convex lens, calculate the new size of the image

A concave mirror of focal length 20 cm and a convex mirror of focal length 15 cm are placed 50 cm apart,such that the two mirrors face each other .An object is placed exactly midway betwen them.Find teh nature and position of the image formed by reflection first at the concave mirror and then at the convex mirror.

An object of 3 cm length is placed at 10 cm from the ple of a concave irror of focal length 9 cm.Find the size and position of the image.