Physics

Physics

Problem

A convex lens of focal length f=5 cmf = 5\,\text{cm} is used as a simple magnifier. Two object positions are tried: (i) u=4.9 cmu = 4.9\,\text{cm} and (ii) u=4.0 cmu = 4.0\,\text{cm} from the lens. Which statement correctly compares the strain on the observer’s eye in the two cases? a) Case (ii) causes less strain because the angular size of the image is greater. b) Case (i) causes less strain because the eye views an image nearly at infinity. c) Case (ii) causes practically no strain since the image forms at the least distance of distinct vision (≈25 cm\approx 25\,\text{cm}). d) Case (i) actually causes more strain since the eye has to focus on a very distant image.

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