(a) An object is placed well outside the principal focus of a convex lens. Draw a ray diagram to show how the image is formed, and say whether the image is real or virtual.(b) What is the effect on the size and position of the image of moving the object (i) towards the lens, and (ii) away from the lens?
(a) When an object is placed well outside the principal focus of a convex lens, the image formed is real and inverted as shown in the figure.
(b) The effect on the size and position of the image:
(i) If an object is moved towards the lens, then the position of the image starts moving away from the lens, towards infinity (on the right side of the lens), and the image size will keep on increasing till the object reaches focus.
After that, when the object is moved closer to the lens, the image is formed behind the object (left side of the lens). This image is virtual, erect, and magnified in size.
(ii) If an object is moved away from the lens, the image size will keep on decreasing and the image keeps on shifting towards the lens.
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