Shadows:
Shadow: Dark patch formed behind an opaque body, when the opaque body is placed in the path of light is called shadow.
¶¶ Conditions for the formation of shadow:
1) There must be source of light
2) There must be an opaque body to obstruct the path of light.
3) The must be an opaque screen to receive the shadow as it cannot be formed in air.
Kinds of shadow:
There are two kinds of shadow:
1.Umbra: A region of total darkness, formed behind an opaque body, is called umbra. No light rays of light reaches in this region.
2.Penumbra: A region of partial darkness, formed behind an opaque body, is called penumbra.
Some rays of light always reach in this region and partially illuminate it.
¶¶ Eclipse: The shadow cast by the heavenly bodies on each other is called an eclipse.
1.Lunar eclipse:When the earth comes in between sun and the moon, lunar eclipse is formed. It is formed on “Full moon night”.
2.Solar eclipse:When the moon comes in between the sun and the earth, solar eclipse is formed. It is formed on new moon day.