Question

How are shadows formed? What are the two types of shadows based on the source of light? Do all objects cast shadows?

Answer 1

1. A shadow is just a space or region where there is no light since an opaque object blocks light rays.
2. The position and intensity of the source of light affect the properties of the type of shadow that is formed.
3. Light sources can be either point or non-point (extended) in nature. If it is a point source of light, then it forms a simple shadow called an umbra.
4. If the light source is an extended light source, the shadow is divided into the umbra, penumbra, and ant-umbra. They can also be used to define levels of darkness, as is sometimes done when dealing with sunspots.
5. No, only opaque objects can cast a shadow.