A source of light, capable of producing a shadow of an object that typically contains two parts namely, an umbra, and a penumbra is known as an extended source of light. To understand the nature of an extended source of light, suppose an object is placed between a screen and an extended source of light. When the light radiations emitted by the light source strike on the surface of the object, a portion of the light radiations gets absorbed, while a part of the light bounces back. This reflection and absorption of light radiations majorly depend on the nature or texture of the object. If the object is opaque in nature, a shadow gets formed on the surface of the screen. The middle portion of the shadow that lies in the same level as that of the object dimensions is known as umbra; whereas, the rest parts of the shadow are called the penumbra. The umbra portion of the shadow is comparatively darker, while the penumbra part is lightly shaded.
Extended Sources of Light Examples
There are a variety of extended sources of light present around us. Some of them are listed below:
1. Tube Light
Tube light is one of the prime examples of extended sources of light used in our daily life as it is a collection of multiple point sources of light.
The shadow of an object that is placed in front of a candle usually consists of two parts, namely umbra and penumbra. This implies that a candle is yet another example of the extended sources of light used in our daily lives.
Sun is one of the prominent examples of extended sources of light present around us.