Question

an object is at a distance 15cm from a convex lens of focal length 30 cm the position of the image formed by it will be

Answer 1

given,

object distance, u = 15 cm

focal length,f= 30 cm

from mirror formula,

$\frac{[tex]\frac{1}{f}=\frac{1}{v}-\frac{1}{u}$

1}{v}=\frac{1}{f}+\frac{1}{u}\\   v=\frac{fu}{f+u}\\ v=\frac{30\times{15}}{30+15}\\ v=\frac{450}{45}\\ v=10 cm[/tex]

thus, the image will be formed 10 cm from the optical center

Answer 2

the image will be between the focus and centre of curvature