Question

19. Rays incident on ........... diverges from a focal plane of concave lens.
A) Focus
B) Parallel to principal axis
C) Parallel rays making some angle with principal axis
D) Through centre of curvature​

Answer 1

Answer:

Having passed through the lens the rays intersect at a point 15 cm from the lens. If the lens is removed, the point where the rays meet will move 5 cm closer to the mounting that holds. Find the focal length ( in cm) of the lens without sign.