Question

the distance of the object AB from the optical center O is 45cm and image formed at a distance 90 cm then the focal length is ,​

Answer 1

Explanation:

u=-45cm

v=90cm

Since the image is virtual therefore, it must be a convex lens

f

1

=

v

1

−

u

1

f

1

=(

90

1

)−(−

45

1

)

f=30cm

m=

u

v

=(

−45

90

)=−2

m=

h

o

h

i

−2=

5

h

i

h

i

=−10cm