A convex lens is placed between an object and a screen which are a fixed distance apart. For one positioin of the lens the magnification of the image obtained of the screen is m_(1). When the lens is moved by a distance d, the magnification of the image obtained on the same screen is m_(2). The focal length of the lens is (m_(1)gtm_(2))

A convex lens is placed between an object and a screen which are a fix

1.	A convex lens is placed between an object and a screen which are a fixed distance apart. For one positioin of the lens the magnification of the image obtained of the screen is m_(1). When the lens is moved by a distance d, the magnification of the image obtained on the same screen is m_(2). The focal length of the lens is (m_(1)gtm_(2))
Answer» `d/((m_(1)-m_(2)))` `d/((m_(1)+m_(2)))` `d (m_(1))/(m_(2))` `d (m_(2))/(m_(1))` ANSWER :C

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