Question

14) At what distance from a concave lens from a concave lens of focal length 20 CM tall object be placed so as to obtain its image at 15 CM from the lens? Also calculate the size of the image formed. Draw a ray diagram to justify your answer for the above situation and label it​

Answer 1

Answer:

Thus, object should be placed at 60 from the lens

Explanation:

f= -20 ,v=-15 , h= 6

Solution -

using Lens formula,

1/f = 1/v + 1/u

u = vf/f-v

= -15×-20/-20-(-15)

= 300

Thus, object should be placed at 60 from the lens .

m= h'/h=v/u

h'= 15/60×6

= 6/4