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JEE Main20204 Sep 2020Evening ShiftPhysicsRay OpticsActual

The distance between an object and a screen is 100 cm . A lens can produce real image of the object on the screen for two different positions between the screen and the object. The distance between these two positions is 40 cm . If the power of the lens is close to N 100 D where N is an integer, the value of N is _________

Correct answer

0

Step-by-step solution

f = D 2 - d 2 4 D = 100 2 - 40 2 4 ( 100 ) = ( 100 + 40 ) ( 100 - 40 ) 4 ( 100 ) = 21   cm P = 1 f = 100 21 = N 100 N = 476 . 19

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