Question

State whether true or false?
The two parts of a shadow are penumbra and antumbra.
(A) True
(B) False

Answer 1

Hint:Shadow occurs when a body comes in between the path of light and the body is smaller as a comparison to the width of the path of light. In such a case a shadow is formed and sometimes we see that light enters the space of geometrical shadow. This happens due to refraction of light.

Complete step by step answer:
The penumbra is the lighter outer part of a shadow. For example, consider the case of the sun, moon and earth. The Moon's penumbra causes partial solar eclipses, and the Earth's penumbra is involved in penumbral lunar eclipses. Whenever a shadow is formed, we can broadly classify the shadow into 3 distinct parts, these are the umbra, the penumbra, and the antumbra. Now we see in detail all of them. The penumbra is a half-shadow that occurs when a light source is only partly covered by an object – for example, when the Moon covers the part of the Sun’s light. The umbra is the shadow dark portion- for example in case of diffraction of light the pattern on the screen is formed, the dark part is completely dark and is an example of umbra. The antumbra is the lighter part of the shadow that begins where the umbra ends.
Hence in light of above knowledge the given statement is true.

Note: The size of the penumbra increases with the distance between the source and the obstacle. Umbra and penumbra both have to do with light and shadows on Earth and in space. Not all shadows are totally black and lighter areas in a shadow are called penumbras.