A convex lens is placed on an optical bench and is moved till it gives a real image of an object at a minimum distance of 80 cm from the latter. Find

Monjur Alahi

A convex lens is placed on an optical bench and is moved till it gives a real image of an object at a minimum distance of 80 cm from the latter. Find the focal length of the lens. If the object is placed at a distance of 15 cm from the lens, find the position of the image.


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Salim Ahmed Kawsar

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Correct Answer - `f = 20`, virtual and erect image at 60 cm from the lens on the same side as the object

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