Page 138 - Active Science 5 Ebook and Activity

Let’s Pronounce Together
The above activity shows that if a source of light is
far from the object, then the size of the shadow of the luminous non-luminous

object is smaller than the object. But if the source of transparent translucent
light is close to the object, then the size of the shadow opaque shadows
is bigger than the object. light source partially

LET’S
REVISE

• Materials are grouped as transparent, translucent and opaque according to the amount of
light allowed by them to pass through.

• Opaque objects block the light falling on them.
• Shadows are formed only by translucent and opaque objects.
• Shadows are always dark.

• Shadows are formed on opposite side of the source of light.

Glossary

• Luminous objects : The objects which emit or produce their own light.
• Non-luminous objects : The objects which do not produce their own light.
• Transparent objects : Objects through which light can pass completely.
• Translucent objects : Objects that allow light to pass partially through them.

• Opaque objects : Objects which block the light and do not allow light to
pass through them.

• Shadow : A shadow is a dark shape formed by a translucent or an
opaque object by blocking the light falling on it from a
light source.

Practice Time

A. Tick the correct option.

1. Objects which do not produce their own light are called _____________.
a. transparent b. luminous
c. non-luminous d. opaque

2. Objects which allow light to pass through them are_____________.
a. translucent b. transparent

c. opaque d. luminous
3. Which of the following is a translucent object?

a. Butter paper b. Clear glass
c. Wood d. Mirror

138 Active Science-5