Page 199 - New Medley 3 Semester 2

bulb and a glowing tubelight are some luminous Knowledge Zone

objects. A fi refly or jugnoo is an insect that

e things that do not have light of their own glows very bright and is a natural
are called nonluminous objects. Schoolbag, luminous object.

dress, chalk, pencil and blackboard are some
nonluminous objects.

Shadows
Hang a ball in a dark room with the help of a

string. Now, light a torch on the ball. What do

you see on the wall? You will nd a dark patch

of the ball on the wall. is dark patch is the
shadow of the ball. us, the dark shape of an

object made on a surface is called shadow.

Features of shadow

 A shadow is always
formed on the opposite

side of the source of light.

 A shadow becomes shorter
as the object moves away

from the source of light.

 A shadow is always black.
It does not have any colour

in it. Shadow in the evening Shadow at noon Shadow in the morning
 A shadow is longer in the morning and evening and the shortest at noon.

1 • Critical Thinking

Write Yes or No
1. Burning candle is a natural source of light.

2. Opaque objects make shadows.

3. A shadow is always formed behind the source of light.

4. At noon, the shortest shadow is formed.

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