# Move the Screen!

A thin convex lens of focal length $$25 \text{ cm}$$ is inserted between a luminous point object and a screen separated by $$100 \text{ cm}$$. The lens forms a sharp image of the object on the screen. When a thin glass plate is introduced between the object and the lens, the screen has to be shifted away by $$2 \frac{4}{23} \text{ cm}$$ to form a sharp image on the screen. If instead of this, we put the same glass plate between the lens and the screen, by what distance (in cm) should the screen be shifted to form a sharp image of the object on the screen?

×