Light, Shadows and Reflections

Light, Shadows and Reflections

Session by Khadepau Aanya

First of all Answer a simple question.

Multiple Choice

What is light

• A source that makes us blind.

• A source that makes things visible.

There are two types of sources based on to emit light:

• Luminous Objects

• Non-Luminous objects

Luminous Objects

• Objects that emit their own light are known as luminous objects.

• Example: Sun and other stars

Non-luminous objects

• Objects that do not emit light and reflect the light produced by luminous objects are known as non-luminous objects

• Examples: moon, trees, buildings

Objects can be classified into three groups:

• Translucent objects

• Transparent objects

• Opaque objects

Transparent objects

• Objects which allow light to pass through them completely are called Transparent

• We can see through them clearly.

• Example: Clear Water

Translucent objects

• Objects which allow light to pass through them partially are called Translucent objects.

• We can see through them partially.

• Example: Coloured Glass

Opaque objects

• Objects which do not allow any light to pass through them are called Opaque objects.

• We cannot see through them.

• Example: Wall

Shadows

• A shadow is the region of ''absence of light''.

• When an opaque object blocks a path of light, then a shadow is forrmed.

Characteristics of a Shadow

• It is always black, regardless of the colour of the object used to make the shadow.

• It only shows the shape or outline of the object and not the details.

• The size of a shadow varies depending on the distance between the object, the source of light and the screen.

Image

• An image is formed by intersection of reflected rays.

• Image is seen when reflected rays approach to observer's eyes.

•  Image gives more information such as colour, structure etc.

• Image can be straight or inverted.

Reflection

• We say light is reflected when it bounces off a surface.

• Reflection of light helps us to see most of the things around us.

• Also known as lateral inversion.

• 
  

Pinhole camera

• A pin-hole camera is just a box with a very tiny hole on one of its sides.

• Light falls on the hole, and an inverted image is formed on the side opposite to the hole. 

• The human eye acts very much like a pin-hole camera.

Thank you!

Hope you enjoyed!!!