What is the focal length of a magnifying glass that produces an angular magnification of 7.0 x when used by a person with a near point at 28 cm?
A) 2.0 cm
B) 3.0 cm
C) 4.0 cm
D) 5.0 cm
E) 6.0 cm

Question

Quizplus · Accepted Answer

The angular magnification (M) of a magnifying glass is given by M = 1 + (D/f), where D is the near point distance (28 cm) and f is the focal length. Solving 7 = 1 + (28/f) gives f = 4 cm.

What Is the Focal Length of a Magnifying Glass That