Question

Give reason

We get both the umbra and the penumbra regions in the shadow of an opaque object when we use a finite source of light.

Answer 1

1. The terms umbra and penumbra refer to two different types of shadow zones with varying levels of light. The region of the shadow where the shadowing item blocks all of the light from the source is called a "umbra."
2. The zone around the umbra where the shadow is merely partial, or imperfect, is referred to as a "penumbra."
3. For Finite source - When the light source is greater than a single point, you get them. These appear because, while the shadowing item blocks part of the light from the source, it does not block all of it.