A card sheet divided into squares each of size 1 mm 2 is being viewed at a distance of 9 cm through a magnifying glass (a converging lens of focal length 9 cm) held close to the eye.

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KollegeApply · Accepted Answer

(a) f = 10 cm, u = -9 cm 1/v-1/u=1/f 1/v=1/f+1/u = $\frac{1}{10}$-$\frac{1}{9}$= -$\frac{1}{90}$ $\therefore$ v = – 90 cm Linear magnification = v/u = -$\frac{90}{9}$= 10 Area of each square in the image = (1 mm x 10) 2 = 100 mm 2 = 1cm 2 (b) Angular magnifìcation = D/|u|=$\frac{25}{9}$ ≈ 2.8 (c) No. if the image is located near the least distance of distinct vision (v = D = 25 cm), the two quantities in (a) and (b) are equal

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