reflection and refraction

Question 1

What is the incident ray

Answer 1

The incoming light ray onto the mirror

Question 2

What is the reflected ray

Answer 2

The light ray that is reflected from the mirror

Question 3

What is the normal

Answer 3

The line perpendicular to the mirrors surface, at the point where the light ray is reflected

Question 4

Angle of incidence and angle of reflection

Answer 4

theta/θ i and theta/θ r

Question 5

when does reflection occur

Answer 5

Reflection occurs when light, sound, or other waves encounter a boundary and bounce back.

Question 6

What is a refraction

Answer 6

Often when a wave travels from 1 medium to another, it will speed up or slow down. This can cause refraction. Eg. when a wave crosses a boundary between 2 different media such as air to water, it can change direction

Question 7

What is the refractive index

Answer 7

The refractive index is a measure of how much light or other forms of radiation are bent, or refracted, when they enter a medium. The refractive index is always greater than or equal to 1. A refractive index of 1 implies that the light travels at the same speed in the medium as it does in a vacuum. As the refractive index increases, the speed of light in the medium decreases, and the bending of light becomes more pronounced. This only works from air to a new medium.

Question 8

If a wave speeds up when it goes into a new median which way will it bend to

Answer 8

it bends away from the normal ray

Question 9

If a wave slows down when it goes into a new median which way will it bend to

Answer 9

it bends towards the normal ray

Question 10

How to work out the refractive index

Answer 10

snells law n = sin of incident ray / sin of refracted ray

Question 11

What is dispersion

Answer 11

When white light refracts it can split up into different parts of the spectrum. It causes different colours to appear due to different wave lengths as they change speed differently when changing medium

Question 12

method for light going through the perspex semi circle and finding out about the incidence and refractive ray

Answer 12

draw around the perspex semi circle on paper, and add a normal line half way along the straight edge using a protractor

send a light ray from the ray box in along the normal ray

Mark the position of both the incident and refracted rays with 2 points.

remove the perspex block, and trace the refracted ray back to meet the incident ray

repeat for difffernet angles of incidence (increasing by 10% each time)

plot a graph of angle of refraction against angle of incidence