An object is there on a wall. Now by help of convex lens, an image of object is obtained of same size as of object on the opposite parallel wall. If the lens is at distance d from second wall, then what should be the focal length of lens ?

An object is there on a wall. Now by help of convex lens, an image of

1.	An object is there on a wall. Now by help of convex lens, an image of object is obtained of same size as of object on the opposite parallel wall. If the lens is at distance d from second wall, then what should be the focal length of lens ?
Answer» `d/4` `d/2` more than `d/4` but less than `d/2` less than `d/4` SOLUTION :By substituting v=d in lens equation =`1/f=1/v-1/u`and for image of same size of object, TAKING \|v\|=\|u\|=d u=-d (From SIGN convention) `therefore1/f=1/d=((1)/(-d))` =`1/d+1/d` `therefore1/f=2(1/d) thereforef=d/2`

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An object is there on a wall. Now by help of convex lens, an image of object is obtained of same size as of object on the opposite parallel wall. If the lens is at distance d from second wall, then what should be the focal length of lens ?

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