Question

please give me answer for this question​

Answer 1

V=45cm

U=-90cm

h=2cm

h'=?

f=?

Therefore to find the focal length we would use lens formula

i,e; 1/f=1/v-1/u

1/f=1/45-1/(-90)

1/f=1/45+1/90

1/f=2+1/90

1/f=3/90

1/f=1/30

f=30cm

Now,

To find height of the image we would use height formula

i,e; h'/h=v/u

h'/2=45/-90

h'=45*2/-90

h'=-1cm

And the lens used here is convex lens becoz focal length is positive