Physicsmedium · Past Paper
A lens of power +2.5 D is used by a person. What is the type of defect and the focal length?
AMyopia, -40 cm
BHypermetropia, +40 cm
CMyopia, +40 cm
DHypermetropia, -40 cm
✓ Correct Answer: B — Hypermetropia, +40 cm
Positive power indicates a convex lens used for Hypermetropia. f = 1/2.5 = 0.4 m = 40 cm.
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