A convex lens is placed between an object and a screen which are a fixed distance apart. For one position of the lens the magnification of the image obtained on the screen is m_1. When the lens is I 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 gt m_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 position of the lens the magnification of the image obtained on the screen is m_1. When the lens is I 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 gt m_2)
Answer» `(d)/((m_1 - mu_2))` `(d)/((m_1 + m_2))` `d m_1/m_2` `d m_2/m_1` ANSWER :A

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