For which position of the object does a convex lens form a virtual and erect image ? Explain with the help of a ray diagram.
Such an image is formed when the object lies between the optical centre and the principal focus. Consider two rays one moving parallel to the principal axis and the other passing through the optical centre. After refraction the two rays seem to meet on the same side as that of the object. Thus, the image lies on the same side as that of the object.The image is virtual, erect and magnified. The ray diagram is as shown.