Question

b) An object is placed 20cm away from a convex lens whose focal length is 10cm
represent the above situation in ray diagrams and guess the position and nature of the
image.(2M)​

Answer 1

Answer:

It is to be remembered that a convex mirror always forms the virtual, erect and diminished image.

Given: Object distance, u=−10cm Focal length, f=15cm

To find: Image distance, v

From mirror formula :

v

1

+

u

1

=

f

1

v

1

−

10

1

=

15

1

v

1

=

15

1

+

10

1

=

150

25

v=6cm

Hence image will be formed 6 cm beyond the mirror, i.e virtual magnification

m=

u

−v

=

−10

−6

=0.6

Hence it will be erect and diminished.