A real, inverted image of the size of object is to be formed by holding the object at 1 meter from a convex lens, What should be the focal length of the lens? Draw the course of rays.

A convex lens produces an inverted image of size 1.4cm The size of object is 0.7cm. If the object is at distance 30 cm from the lens. Calculate focal length of the lens

A convex lens is used to focus the rays from the far off light bulb at a distance of one meter from the lens. What should be the focal length of the lens ? Draw a ray diagram to show the formation of image.

Draw ray diagram showing the image formation by a convex lens when an object is placed at twice the focal length of the lens.

A convex lens produces a real image m times the size of the object. What is the distance of the object from the lens ?

The same size images are formed by a convex lens when the object is placed at 20cm or at 10cm from the lens. The focal length of convex lens is ____ cm

An object is there on a wall. Now by help of convex lens, an image of object is obtained of same size as of object on the opposite parallel wall. If the lens is at distance d from second wall, then what should be the focal length of lens ?