A person with normal eyesight uses a converging lens of focal length 10 cm. He holds the lens close to his eyes to finish an engraving job. What is the magnifying power of the lens?
A) 3.5
B) 4.5
C) 6.5
D) 7.5
E) 8.5

Question

Quizplus · Accepted Answer

The magnifying power (M) of a lens is given by the formula M = 1 + (D/f), where D is the least distance of distinct vision (usually 25 cm for a person with normal eyesight) and f is the focal length of the lens. Substituting the given values, M = 1 + (25/10) = 1 + 2.5 = 3.5.

A Person with Normal Eyesight Uses a Converging Lens of Focal