Refraction Of Light
Chapter Name : Light-Reflection And Refraction |
Sub Topic Code : 101_10_10_03_02 |
Topic Name : Refraction Of Light |
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Sub Topic Name : Refraction Through A Rectangular Glass Slab |
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Introduction
Like reflection, refraction of light also follows a set of rules, known as laws of refraction.
Pre-Requisites:
Introduction about refraction of light.
Activity:
Take a glass slab, observe a object from other side of the slab, and comment about the position of the object.
Real Life Question:
“Why we see the objects in the sky, displaced from their position?” “Why we see a coin raised up a little bit in the bucket full of water?”
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Snell’s law | Ratio of sine of angle of incidence to the sine of angle of refraction for a particular pair of medium. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Glass plate | When we observe a paper through the glass plate we see the letters raised, is due to the refraction. |
Real life uses :
In optometry, to detect the eye’s error and also to correct it. Useful in propagation of sound in the water.
Places to visit :
You can see the various examples of refraction at your home itself. Coin in the bucket of water, broken pencil, raised letter under glass plate, a glass slab etc.
Practical examples around us
| Examples | Explainations |
|---|---|
| Rainbow | Seven colors of the rainbow are due to the refraction itself. |
| Mirages | A natural phenomenon in which we see the object displaced from its position. |
What you learn in Theory:
When ray of light enters into a glass medium it bends towards the normal and when it enters the air from the glass slab, it moves away from the normal.
What you learn in Practice:
Speed of light changes when it changes the medium of propagation. This is the basic principal of various examples of refraction around us.