Question
A conversing beam of rays is incident on a diverging lens. Having passed though the lens the rays intersect at a point 15 cm from the lens on the opposite side. If the lens is removed the point where the rays meets will moves 5 cm closer to the lens. The focal length of the lens is
-
-10 cm
-
20 cm
-
-30 cm
-
5 cm
Solution
C.
-30 cm
Given u = 10 cm, v = 15 cm
