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What focal length gives a magnification of 6 when the eye views at the 25 cm near point?
A5 cm
B6 cm
C2.5 cm
D25 cm
Answer & Solution
Correct answer: A. 5 cm
m = 1 + D/f = 6 gives D/f = 5, so f = 25/5 = 5 cm.
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