An object is placed at a distance of 20 cm from a thin double convex l – InterviewSolution

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1.	An object is placed at a distance of 20 cm from a thin double convex lens of focal length 15 cm. Find the position and magnification of the image.
Answer» Given that u = 20 cm, f = 15 cm `(1)/(f)=(1)/(v)+(1)/(u)` `(1)/(v)=(1)/(f)-(1)/(u)=(1)/(15)-(1)/(20)` `(1)/(v)=(20-15)/(15xx20)=(5)/(15xx20)` `(1)/(v)=(1)/(60)` `"v = 60 cm."` `"Magnification (m) "=(-v)/(u)` `m=(-60)/(-20)(u=-20cm)` m = 3

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