Page 155 - Science Class 06

Opaque Materials

Most materials are opaque. When light
strikes an opaque object none of it passes 1. Give examples of two luminous and two
through it. Most of the light is either non-luminous objects.
reflected or absorbed by the object and 2. What is a transparent material?

converted to heat. Materials such as wood, 3. Give examples of two opaque materials.
stone and metals are opaque to visible light. 4. What do you mean by the ray of light?

Light Travels in a Straight Line
Light travels in a straight line. This property

of light can be seen in our day-to-day life.
Let’s do an ac vity to understand this
property of light.

Aim : To see light travels in a straight line.

One cannot see through opaque material. Materials required : Three squares of
cardboard about 20 cm of side, a candle.
Use of Opaque Materials
Method : Make small holes at the centre
Opaque materials are used for various of each square. Now, place these
purposes. As far as visibility is concerned, cardboard squares on flat wooden
opaque materials are used where we do not surface in a straight line so that you

want to allow light to pass through them. could see through the holes of all the
three cardboards. Now, place a lighted
Ray of Light
candle so that the flame of the candle
The path in which light travels in a par cular could be seen through the holes.
direc on is called ray of light.

Now, displace one of the cardboards
slightly so that the holes are no longer
in a straight line. The flame of the

candle will not be visible now. This
Beam of light : A collec on of a large number ac vity shows that light travels in a
of rays of light is called beam of light. straight line.

Science-6 155