Page 169 - Physics_Form_2

Refraction and dispersion of light
Chapter Five

Refraction and dispersion of light

FOR ONLINE READING ONLY

Introduction

The principles, theories, and concepts surrounding the refraction of light are
integral to our daily lives, significantly impacting both natural phenomena and
technological advancements. Key applications include vision correction, the design
of various optical instruments, the functionality of optical fibres, the creation of
various colours by prisms and rainbows, and the development of magnification
tools. In this chapter, you will explore how light refracts through glass prisms and
lenses. The competencies developed will enable you to design optical instruments
and use them in different contexts.

Think
Importance of optical fibres in our daily lives

Concept of refraction of light determined by using the speed of light
In the previous chapter, it was learnt that, in that medium. Refraction occurs only
as light travels through a given medium, it at a boundary. Once the light has crossed
travels in a straight line. However, when the boundary between the two media, it
light passes from one medium to other continues to travel in a straight line.
medium, the light beam tends to bend.
The bending of light is referred to as the Activity 5.1
refraction of light. The direction of a ray
of light changes as it passes obliquely Aim: To investigate the refraction
from one medium into another. of light rays as they pass

from air to water
Refraction occurs because different Materials: coin, bucket, water
media have different optical densities. If
the speed of light in one medium is lower Procedure
than that in the other medium, the first 1. Obtain a wide opaque container, such
medium is said to have a higher optical as a bucket.
density than the second medium. Thus, 2. Place a coin inside but at the bottom
the optical density of a medium can be of the empty bucket.

163

Physics Form 2 Final.indd 163 25/10/2025 10:27