Law of Reflection

Ray Model of Light -Law of Reflection

How do light rays behave when they undergo reflection?









HW - Interactive Lesson on Reflection
GSS108

Intro video - which is the showing the lab we will be doing next - BE SURE TO WATCH ENTIRE VIDEO

Let's go over some important terms!

• What is the normal line?

• What is the incident ray?

• What is the reflected ray?

• Where is the angle of incidence?

• Where is the angle of reflection?

Multiple Choice

The normal should be drawn using a __________ line.

• solid

• dotted

Multiple Choice

The normal is ___________ to the surface.

• perpendicular

• parallel

Multiple Choice

Which is the ray what strikes the surface?

• Incident ray

• Incidence ray

• Reflected ray

• Reflection ray

Multiple Choice

Which is the ray that is reflected off the surface?

• Incident ray

• Incidence ray

• Reflected ray

• Reflection ray

Law of Reflection

The angle of incidence is equal to the angle of reflection (i = r)

The incident ray, the reflected ray and the normal at the point of incidence all lie on the same plane.

Multiple Choice

What does the Law of Reflection state?

• The angle of incidence is larger than the angle of reflection.

• The angle of incidence is equal to the angle of reflection.

• The angle of incidence is smaller than the angle of reflection.

Multiple Choice

What is A?

• Angle of incidence
• Angle of reflection
• Incident ray
• Reflected ray

Multiple Choice

In the diagram, which letter represents the angle of incidence?

• B

• C

• D

• E

Multiple Choice

What is the line MN called in the given diagram

• incident ray

• reflected ray

• reflecting surface

• normal

Multiple Choice

The ray that bounces off the mirror.

• Angle of Reflection

• Incident Ray

• Reflected Ray

• Angle of Reflection

Multiple Choice

The ray of light that strikes a mirror.

• Reflected Ray

• Incident Ray

• Angle of Incidence

• Angle of Reflection

Multiple Choice

Zoom in to see question.

• A

• B

• C

• D

Multiple Choice

If the angle of reflection is 35 degrees, what is the angle of incidence?

• 35

• 55

• 90

• 0

Fill in the Blanks

Multiple Choice

In the given figure, which of the following is TRUE? Remember - the angles are measured from the normal!

• The angle of incidence is 10°.

• The angle of incidence is 80°.

• The angle of reflection is 10°.

• The angle of reflection is 90°.

What happens when the reflecting surface is rough?

What happens when the reflecting surface is smooth vs. rough?
BE SURE TO WATCH ENTIRE VIDEO

Smooth Surface

Regular (specular) Reflection

All light rays are reflected in the same direction

Clear images are formed

Rough Surface

Irregular / Diffused Reflection

All light rays are reflected in different directions

Note- the Law of Reflection is still true!

No image is formed

Multiple Choice

In which type of reflection will we be able to see an image?

• regular

• diffused

Multiple Choice

Which is a rough surface?

• mirror

• glass

• still water

• silk

Review questions

Multiple Choice

Which image shows diffuse reflection?

In this example - what is the angle of reflection?
Remember - the angles are measured from the normal!

Multiple Choice

In the given figure, is the law of reflection true?

• No, the angle of incidence does not equal the angle of reflection

• Yes, the angle of incidence does equal the angle of reflection

Multiple Choice

In the given figure, what is the angle of reflection?

Remember - the angles are measured from the normal!

• 33 degrees

• 57 degrees

Multiple Choice

In the given figure, what is the angle of reflection?

Remember - the angles are measured from the normal!

• 35 degrees

• 55 degrees

• 70 degrees

Multiple Choice

In the given figure, what is the angle of reflection?

Remember - the angles are measured from the normal!

• 30 degrees

• 60 degrees

• 70 degrees