Question

The image formed by the convex lens of an object placed in front of it, at

10 cm, is virtual, erect and twice the size of the object. What will be the

position of image formed? What will be the new position of image and its

magnification if object is shifted at 20 cm in front of lens?​

Answer 1

Answer:

Given:u=−10cm f=20cm (convex lens)

To find: v and image's nature.

Solution: From lens formula

1/v - 1/u= 1/f

1/v + 1/10= 1/20

1/v= -1/20

v=−20cm

And magnification = v/u =2

Hence image formed is virtual, erect and magnified two times.