Light/Rays (Reflection, Refraction, TIR)

Question 1

What happens in specular reflection

Answer 1

If all light rays are parallel when reflected off a surface there will be an image produced

Question 2

What happens in diffuse reflection

Answer 2

When the surface isn’t flat light is scattered by a surface in lots of different directions and no image is formed

Question 3

Name the two different types of reflection

Answer 3

Diffuse and specular

Question 4

What is total internal refraction

Answer 4

Beyond a certain angle (critical angle) all waves will refract at an angle larger than 90 degrees and therefore reflect back into the glass. TOTAL INTERNAL REFRACTION

Question 5

What causes the angle of refraction to be smaller?

Answer 5

Light slows down (enters a more optically dense material) and the light is refractedcloser to the normal

Question 6

What causes the angle of refraction to be larger than the angle of incidence?

Answer 6

Light speeding up (entering a less optically dense material) and the light is refracted further from the normal

Question 7

What is the law of reflection?

Answer 7

The angle of incidence = The angle of reflection

Question 8

What is the angle of reflection?

Answer 8

The angle between the reflected light ray and the normal

Question 9

What is the angle of incidence?

Answer 9

The angle between the incoming light ray and the normal

Question 10

What happens to the light in a converging/ convex lens

Answer 10

This type of lens brings light together.
It is used in glasses or longsighted people

Question 11

What happens to light in the concave or diverging lens

Answer 11

This type of lens brings light together
It is used in glasses or shortsighted people

Question 12

What are the rules for a connverging/ convex lens (lens diagrams)

Answer 12

1.A ray going in parallel to the centreline is redirected out through the far side focus
2. A ray going to the centre keeps going straight
3.A ray going through the nearside focus goes out parallel to the centreline
4.where the lines crossed there is an image if you have to go backwards, do!

Question 13

What are the rules for a diverging/concave lens (lens diagrams)

Answer 13

1. A ray going in parallel to the centre line is redirected away from the nearside focus
2. A ray going to the centre keeps going straight
   3.Where the lines crossed there is the image

Question 14

What is refraction

Answer 14

The process where we describe the way light changes speed and direction as it moved from one material to another

Question 15

In what situations can total internal reflection take place

Answer 15

When light is travelling from a high refractive index to a low refractive index
Eg. Glass to air