Question

3. A convex lens has a focal length of 10 cm At what distance from the lens should the object be
placed so that it forms a real and inverted image 20 cm away from the lens? What would be the size
of the image for med if the object is 2 cm high? With the help of a ray diagram show the formation
of the image by the lens in this case.​

Answer 1

Answer:

f=+10cm,v=+20cm as image is real and inverted.

Height of the object =2cm(say+ve)

Using

f

1

=

v

1

−

u

1

, we get

u

1

=

v

1

−

f

1

=

+20

1

−

10

1

=

20

+1−2

=

20

−1

=−20cm(=2f)

Image will be of the same size as that of object (as u=v ) and hence, the height of the image

Explanation:

hope you have understood that