Question

An object of height 2 cm is kept at 30 cm from a convex lens. It's real image is fromed at 60 cm from the lens. Find the focal length and power of the lens​

Answer 1

Step-by-step explanation:

Here,

Image distance=v=20cm,

Object distance=u=−30cm,

Lens equation is given by,

v

1

−

u

1

=

f

1

,

putting the values we get,

20

1

−

−30

1

=

f

1

,

∴f=12cm

∴ Focal length of convex lens=f=12cm