A convex & a concave lens are brought it close contact along their optical axes. The focal length of the convex lens is 10 cm. When the system is placed at 40 cm from an object, a sharp image of the object is formed on a screen on the other side of the system. Determine the optical power of the concave lens if the distance  betweenthe object & the screen is 1.6m.

A convex & a concave lens are brought it close contact along their opt

1.	A convex & a concave lens are brought it close contact along their optical axes. The focal length of the convex lens is 10 cm. When the system is placed at 40 cm from an object, a sharp image of the object is formed on a screen on the other side of the system. Determine the optical power of the concave lens if the distance  betweenthe object & the screen is 1.6m.
Answer» ANSWER :`-20/3D=-6.7D`

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