A convex mirror of focal length F1 is placed at a distance d from a convex lens of focal length F2. A beam of light rays coming from infinity falling on convex lens-convex mirror combination and returns black to infinity. Distance d is
Answer & explanation
Correct answer: option 3
The situation can be presented in a ray diagram as shown
From the figure d + 2F1 = f2
$\Rightarrow$ d = f2 - 2F1