A convex lens of power 4D is placed at a distance of 40 cm from a wall at what distance from the lens should a candle be placed so that its image is formed on the wall?

A convex lens of focal length 20 cm is placed at a distance of 24 cm from the screen how far from the lens should an object be placed so as to from a real image on the screen. Also find the nature and magnification of the image produced.

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.

A concave mirror produeces a real image of magnificaion 1//2 ,when an object is placed at a distance of 60 cm from it.Where should the object be placed ,so that a virtual image of double the size is formed by the miror?

An object is placed at a distance of 75 cm from a screen .Where should a convex lens of focal length 12 cm be placed so as to obtain on the screen?

An object is placed at a distance of f//2 from a convex lens .The image will be

A concave lens has focal length of 15 cm. At what distance should the object from the lens be placed so that it forms an image at 10 cm from the lens? Also find the magnification produced by the lens.

An object of 3 cm height is placed at a distance of 60 cm from a convex mirror of focal length 30 cm.Find the position and size of the image formed.

An object is placed at a distance of 10 cm from a convex mirror of focal length 15 cm. Find the position and nature of the image

An object is placed at a distance of 10 cm from a convex mirror of focal length 15 cm. Find the position and nature of the image