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A watch repairer kept a magnifying glas...

A watch repairer kept a magnifying glass very close to his eyes and found that the magnifying power of the glass was 8. if the least distance of distinct vision of the eye is 25 cm , calculate the focal length of the lens .

Text Solution

Verified by Experts

Here m=8 and D =25 cm
`therefore m=1+D/f or, 8 =1+(25)/f`
`therefore f=(25)/7=3.57cm`
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