Question

You are given a convex length of focal length 30cm.Draw a ray diagram to show the nature , size and position of image formed when the object is kept at a distance of 45 cm from the lens.​

Answer 1

Answer:

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