Question

Light from which source of light will not have a penumbra?

• A. Point source
• B. The Sun
• C. Wide source
• D. All Sources

Answer 1

The correct option is A

Point source

1. Penumbra: The faint shadow formed around an umbra is called penumbra.
2. The dark shadow formed at the centre is called an umbra.
3. The penumbra is formed only when a broad source of light is used.
4. The sun, bulb etc is an example of a broad/wide source of light.
5. A point Source of light forms a well defined dark shadow called an umbra.

Hence the correct answer is option A.