Question

The shadow formed due to a point source of light has_____.

• A. only umbra region
• B. only penumbra region
• C. both umbra and penumbra regions
• D. depends on the distance of source from the obstacle

Answer 1

The correct option is A

only umbra region

A point source of light casts only a simple shadow, called an "umbra". For a non-point or "extended" source of light, the shadow is divided into the umbra, penumbra and antumbra. A viewer located in the penumbra region will see the light source, but it is partially blocked by the object casting the shadow.