3. What Is
reflection?
• Reflection is the
change in direction of a
wavefront at an
interface between two
different media so that
the wavefront returns
into the medium from
which it originated.
Common examples
include the reflection of
light, sound and water
waves.
4. Uses of
reflection
Reflection is used in mirrors, especially
concave mirrors in vehicles to avoid
accidents on the road. -Reflection is used
in defense by radars where radars send
waves which after reflection get back to
radar then it can interpret technical fighter
jets.
6. What is Refraction?
Refraction is the bending of light as it passes from one medium to
another, such as from air to water or from air to glass. This bending
occurs because light waves change speed when they pass from one
medium to another, due to the change in the optical density of the
medium. The extent of the bending depends on the angle at which the
light enters the new medium and the difference in optical density
between the two media. Refraction is what causes objects to appear
shifted when viewed through a transparent material like a glass of water,
and it's also what makes lenses work in glasses, cameras, and other
optical devices.
Rainbows, Eyeglasses and contact lenses, Magnifying glasses are real life
examples of refraction
The speed of light for all the mediums are shown:-
Medium Speed
of light
km/s
Air 300,000
Water 225,000
Glass 200,000
7. Real life uses of
refraction
• A lens uses refraction to form an image of an
object for various purposes, such as
magnification. Spectacles worn by people
with defective vision use the principle of
refraction. Refraction is used in peepholes of
house doors, cameras, movie projectors and
telescopes.
8. Laws of
reflection
• According to the first law of reflection, the
incident ray, the reflected ray and the normal at
the point of incidence all lie in the same plane
which is perpendicular to the plane of the
reflecting surface.
