Question

the image of an object formed by
conver lens is of the same size as
that of the object. If the image is
formed at distance of 15 cm from long,
I at what distance from the lens is object
placed? Find the focal length of the power of the lens used ?​

Answer 1

Answer:

Same size of image is formed by a convex lens only when the object is placed at a distance u=2f from the optical center and image is also formed at distance 2f on other side of lens.

⟹2f=50

⟹f=25cm

P=

f(m)

1

=

0.25

1

⟹P=+4D