Question

a parallel beam of rays is incident on a convergent lens with a focal length of 40cm. where should a divergent lens with a focal length of 15cm be a place for a beam of rays to remain parallel after passing Pro the two lenses? draw a ray diagram. with equation 1/f=1/f1+1/f2-d/f1f2​

Answer 1

Answer:

an incident ray is approaching focus of a divergent lens then they become parallel to principal axis.

So if convergent and divergent lens focus coincide then the ray will become parallel to principal axis.

Hence x+15=40

x=25cm

Hence divergent lens should be 25 cm behind convergent lens.