Question

Two point surces `S_(1) and S_(2)` are 24 cm apart. Where should a convex lens of focal length 9 cm be placed them , so that the images of both sources are formed at the same place ?

Answer 1

Distance between two point sources of light = 24 cm
Focal length (f) = 9 cm
Radius of curvature (R) = 2f
`R=2xx9=18cm`
`therefore` Converging lens is placed at 18 cm (or) Second position of converging lens `=24-18=6cm.`
`therefore` position of converging lens = 18 cm (or) 6 cm.