A shadow is formed when light is blocked by an object.
Types of Shadows
Glass is a transparent object.
All the light passes through the glass, that is no light is blocked.
Since, no light is blocked by the object, no shadow is formed.
Butter paper is a translucent object.
Only some light passes through the butter paper, that is some of the light is blocked.
Since, some of the light is blocked by the object, a faint shadow is formed.
Wooden box is a opaque object.
No light passes through the wooden box, that is all of the light is blocked.
Since, all of the light is blocked by the object, a dark shadow is formed.
Properties of Shadow
If you don't have a surface, you cannot see the shadow that is formed.
The shadow is always formed opposite to the light source.
A shadow is just the outline of an object, it doesn't give the details of it.
A shadow is always black in color.
The shadow is larger, when we take the object closer to the light source
The shadow is smaller, when we take the object away from the light source
The size of the shadow depends on the position of the object with respect to the light source.
More from Grade 7 Physics
Understand the concepts of water on earth, its sources and groundwater.
Understand the concept of heating effect of electric current. See real world examples where this effect is observed.
Understand the concept of magnetic effect of electric current. Demystify this seemingly magical effect. See it's application in the real world.