A lens with focal length 500 cm is used as a magnifying glas

A lens with focal length 5.00 cm is used as a magnifying glass. (a) To obtain maximum magnification, where should the object be placed? (b) What is the magnification?

Solution

1/p + 1/q = 1/f

1/p = 1/f - 1/q

f = 5.00 cm and q = -25 cm [for a normal eye, is 25 cm]

1/p = 1/5 - 1/-25

p = 4.17 cm

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M = -q / p = 25 / 4.17

= 5.99