Question

16.The image of an object formed by a lens is of magnification -1. If the distance between the
object and its image is 60 cm, what is the focal length of the lens? If the object is moved 20 cm
towards the lens, where would the image be formed? State reason and also draw a ray diagram
in support of
of your answer.
[CBSE (AT) 2016]​

Answer 1

When the object is moved 20 cm towards the lens, so the new object distance will be = 30 cm - 20 cm = 10 cm. Since the new object distance is less than focal length of the lens, thus the image will be virtual, erect and magnified.