The graph shows the relationship between object distance (u) and image distance (v) for an equiconvex lens. The focal length of the lens is
Answer & explanation
Correct answer: option 3
From the graph it can be extracted that for the given convex lens
u = – 10 cm
v = 10 cm
∴ \(\frac{1}{f} = \frac{1}{v} - \frac{1}{u} \)
\(\frac{1}{f} = \frac{1}{10} - \frac{1}{-10} \)
∴ f = 5 cm
∴ focal length = 5.00 cm