Hello my good friends in Stemsocial community 🙋🏾‍♀️.

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Happy to be here again posting in this community. I've been inactive for a very long time due to the problem I'm having with my device. But I'm back with an extra device📱, Samsung Tablet. I'm back fully. 💪🏾.

I'm here to talk about LIGHT WAVE.
First of all, what is light; As we all know, light is a visible form of energy that enables us to see.

Sources Of Light

They are Natural eg firefly

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or Artificial eg Car headlamp.

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Luminous Body: They are bodies that emits light by themselves eg; sun, car headlamp etc.

Non-luminous Body: They are bodies that don't emit light eg we humans.

Types of light ray:

• Parallel: In this type, light passes in parallel lines.
• Convergent: Here,light meets at a point from the source. This can be achieved by the use of a convex lens
• Divergent: Light travels to spread out from the source. A concave lens is used to get this.

Rectilinear Propagation Of Light

It means that light travels in a straight line. To prove this,we will be talking about formation of shadow and eclipse.

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A Pinhole Camera

It is a wooden box which consist of a pinhole & a screen which is opposite the hole.

Magnification Produced By A Pinhole Camera

Magnification is defined as the ratio of size of the image to size of the object. That is

Height of image=Length of Image
Height of object Distance of object

Ih = Il
Oh Od

Example: A boy 1.5 meters tall stands 2.0m in front of a pinhole camera of length 20cm. Calculate the height of his image.

Solñ:
Oh=1.5
Od=2.0
Il=20
Ih=?

.•. ?÷1.5=20÷2
Making ? the subject of formula;
?= 20×1.5÷2
?=15

Reflection of Light Wave

• Regular
• Diffused

Explanation:

Regular Reflection:
Parallel light reflect when parallel light incident. This is due to it is been incidented on a plain surface.

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Diffused Reflection:
In this reflection, parallel light incidented on a rough surface reflects light in all directions.

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Laws Of Reflection

There are 2 laws of reflection.

The first law states that the incident, reflected and normal ray lies on a plane

The second law states that the angle of incidence is equal to the angle of reflection

From the geometry of the second law,
Deviation=180-(i+r)

Principle of Reversibility of light

It states that the path of light is reversible.

Example:
The ray of light incidented on a plain mirror such that the angle of reflection is 25°. What is the deviation of the ray?

Solñ

D=180-(i+r)
i= 25

Since ∆ of incedence i and ∆ of reflection r is equal,

D=180-(25+25)
D=180-(50)
D=130.

Before I end this, let me list the characteristics of image formed on a plain mirror:

• It is real
• It is virtual
• It's laterally inverted
• It is upright
• It has the same distance behind the mirror as the object in front of the mirror
• It has the same size as the object

With that I have come to the end of a few features of light wave. See you in my next post. You're free to contribute and ask questions 🤔❓Byeeee 👋🏾👋🏾👋🏾👋🏾