CBSE Notes Class 6 Science Chapter 8 Light, Shadows and Reflections

Light is a crucial element in our world, essential for seeing and interpreting our environment. It can be emitted from sources like the sun, lamps, and bulbs. When light interacts with an object, it can be absorbed, reflected, or transmitted through it. As a form of energy that travels in straight lines, light enables us to perceive and understand the world around us.

1.0Luminous and Non-Luminous Object

• Luminous Object- Objects that give out or emit light on their own are called luminous objects. Example-Sun, Torch, Electric Bulb
• Non-Luminous Objects- Non-Luminous Objects are those objects that do not emit light of their own. Example-Moon, Man, Chair, etc.

2.0Opaque Object

If we cannot see through an object, it is an opaque object. This is due to the fact that light cannot pass through them. Example-wood, gold, cement.

3.0Translucent and Transparent Objects

• Translucent Objects-The objects through which we can see, but not very clearly, such objects are known as translucent objects. Example-Butter paper, tracing paper.
• Transparent Objects-If we are able to see clearly through an object, then the object is said to be transparent. Example-Glass. Clear Plastic Bottle.

4.0Pinhole Camera

The pinhole camera is a device used to capture pictures of still objects

• The image generated by a pinhole camera is always inverted, meaning it appears upside down.
• The size of image, formed by a pinhole camera depends on:

1. The distance of objects from the pinhole of the pinhole camera. If the distance between the pinhole and screen is decreased, the size of image will decrease and the image will become bright because the light is spread over a small area.
2. The distance between the pinhole and screen of the pinhole camera. If the distance between the pinhole and the screen is increased, the size of the image will become larger, but the image will also become dimmer because the light spreads over a greater area.
3. The brightness of the image produced by a pinhole camera is influenced by the size of the aperture
4. When the size of the aperture of the pinhole is decreased the image becomes dimmer. Because less light reaches the screen, due to this the image becomes less blurry.

-When pinhole size is 0.5 cm the image form is dim and less blurry.

-When the pinhole size is 1 cm the image is brighter but blurry.

5.0Mirrors and Reflections

• Mirrors: Mirrors are surfaces that reflect light to form images. They are typically made of glass with a shiny, reflective coating on one side.
• Reflection: When light hits a mirror, it bounces back. This process is known as reflection.