Question

Give reason
The  penumbra  is  faint.

MSCERT Class 7 General Science Ch 3 Propagation of Light

Answer 1

The penumbra is the incomplete or blemished shadow outside the total shadow of a dark body, as a planet, where the light from the wellspring of brightening is just mostly cut off.

It's just like in a football stadium with light sources from 2 sides so you have 2 shadows.

Independently, each of them can be considered penumbra, and where they cover - that is umbra.

An umbra is an entire shadow, and a penumbra is a fractional shadow. The separation of the question or the light source adds to the quality of the shadow, regardless of its sort.

Answer 2

Answer:

The Penumbra is the incomplete or blemised shadow outside the total shadow outside the total shadow of a dark body , as a planet , where the light from the wellspring of brightening is just mostly cut off