Question

One half of a convex lens is covered with a black paper. How does it affect the image formed by the convex lens ? explain.

Answer 1

The convex lens will form complete image of an object, even if its one half is covered with black paper. But intensity of the image will be less.

Ray of light coming from the object will be refracted by the lower half of the lens. These rays meet at the other side of the lens to form the image of the given object, as shown in the following figure.