Page 138 - Physics_Form_2

Physics for Secondary Schools

Therefore, this throwing back of light from the object and travel parallel along a
from the mirror is called reflection. It is straight line to the mirror. The same rays
possible to see an object because it either reach the eye after reflection, appearing
emits or reflects light. as if originating from the image, resulting
in a very sharp image.
When using a plane mirror, a reflected
FOR ONLINE READING ONLY
ray bounces off the mirror. A plane Incident rays Reflected rays
mirror is a thin glass whose surface (the
bottom/back) is silvered to obtain a shiny
reflecting surface. Figure 4.9 shows
the reflection of light rays from a plane
mirror. A polished metal surface can also
reflect light rays like a plane mirror.

Normal line Figure 4.10: Regular reflection of light

Irregular reflection of light
Incident ray Reflected ray Irregular reflection is the type of reflection
in which light rays meet a rough reflecting
surface. This is shown by the incident
Plane mirror
light rays reflected in different directions
Figure 4.9: Reflection of light on a plane mirror as shown in Figure 4.11. In irregular

reflection, the reflected rays are not
Regular and irregular reflection of light parallel, causing them to scatter in many
There are two types of reflection: regular directions. This results in the formation
or specular reflection, and irregular or
diffuse reflection. of distorted images.
Incident rays
Regular reflection Reflected rays
In regular reflection, the reflecting
surface is so smooth that an image of the
object that reflects the light is very clear.
In regular reflection, all the reflected
rays are in one direction. The rays are
also parallel, as shown in Figure 4.10.
Examples of such surfaces are mirrors Figure 4.11: Diffuse reflection of light
and polished metal surfaces like highly
reflective aluminium sheets. Laws of reflection

The phenomenon of reflection is
When viewing the image of an object fundamental to the behaviour of light
in a plane mirror, rays of light originate and serves as a foundation in the study of

132
Student’s Book Form Two

Physics Form 2 Final.indd 132 25/10/2025 10:27