Notes of Ch 11 Light, Shadows and Reflections Class 6th Science

Revision Notes of Ch 11 Light, Shadows and Reflections Class 6th Science

Topics in the chapter


  • Light
  • Luminous objects
  • Non-Luminous objects
  • Transparent, Opaque and Translucent Objects
  • Characteristics of light
  • Shadow and its properties 
  • Pinhole camera
  • Mirror and types of mirror

Light

→ It is a form of energy which is responsible for seeing objects.

→ When light falls on an object, some light get reflected, this reflected light come to our eyes and we are able to see an object.

→ Example: sun, torch, candle, fireflies and glow worm etc.

Sources of light

(i) Luminous object: The objects which emit their own light is called luminous object.

→ Example: sun, torch bulb, star

(ii) Non-luminous object: The objects which do not emit their own light is called non-luminous object.

→ Example: Moon, shoe, trees.

Types of materials transmit light

→ There are three types of materials which transmit light:

(i) Transparent
(ii) Translucent
(iii) Opaque

(i) Transparent

→ These objects allow light to pass through them in straight line completely.

→  We can see through these objects clearly.

→  Examples: air, water, etc.

(ii) Translucent

→ These objects allow light to pass through them partially.

→ The object is not clearly seen in translucent object.

→ Examples: Tissue paper, frosted glass, butter paper, etc.

(iii) Opaque

→ These objects do not allow light to pass through them.

→ We can’t see the object through this.

→ Examples: wall, door, trees etc.

Characteristics of light

→ Light travels in straight line

→ Light can be reflected

→ Light can be bent

→ The speed of light is 3 × 108 m/sec

→ Light can be polarized

Shadow

→ When an opaque object blocked the path of light it forms a dark portion on the opposite side of the object this dark portion is known as shadow.

Properties of shadow

→ The object must be opaque or translucent

→ Transparent object do not make shadow

→ It is dark in color

→ It is formed opposite to the source of light

→ It gives the information about the shape of object

→ Size of shadow can be increase or decrees by change in distance between object and screen are changed.

Pin hole camera

→ It is a toy device use to study light travels in straight line

Properties of image formed by a Pin Hole Camera

(i) Image formed by a pin hole camera is coloured.

(ii) Image formed by a pin hole camera is inverted.

(iii) Image formed by a pin hole camera is smaller in size.

Rectilinear propagation of light

→ Light travels in a straight line are called rectilinear propagation of light.

Important terms regard rectilinear propagation of light

(i) Ray of light: It is a path along which light travels in the given direction.

(ii) Beam of light: Bunch of ray of light travel in the given direction.

Mirror

→ A mirror is a polished surface which can make the image of an object.

Types of Mirror

(i) Plane mirror: Image formed is of the same size

(ii) Concave mirror: Reflecting surface is bent–in.

(iii) Convex Mirror: Reflecting surface is bulged-out.

Reflection

→ When light falls on a mirror, light wave may change their direction upon the striking surface this phenomena is called reflection.

Watch age fraud in sports in India

GET OUR ANDROID APP

Get Offline Ncert Books, Ebooks and Videos Ask your doubts from our experts Get Ebooks for every chapter Play quiz while you study

Download our app for FREE

Study Rankers Android App Learn more

Study Rankers App Promo