Foundation
Physics Foundation
Light
Question
Umbra and penumbra are clearly visible when
Know your College Admission Chances Based on your Rank/Percentile, Category and Home State.
Get your JEE Main Personalised Report with Top Predicted Colleges in JoSA
Solution
Umbra is the darkest part of a shadow with no light. Penumbra is the lighter, partial shadow. A large light source (like a fluorescent tube) and a small object create both regions clearly. The large source's edges cast overlapping partial shadows (penumbra) around the object's complete shadow (umbra).
Final Answer: The source of light is big and the obstructing object is small