Light Flashcards
What is transmission?
When a wave passes through a medium
What happens when a wave hits an interface?
It will be either transmitted, reflected or absorbed
What is an interface?
A boundary between two materials
What is the law of reflection?
The angle of incidence = the angle of reflection
What is an incident ray?
The ray shone at an object
What is the angle of incidence?
The angle between the normal and the incident ray
What is the normal?
A line at 90° to the surface a ray hits
What is the angle of reflection?
The angle between the normal and the reflected ray
What is refraction?
The change in the direction of a wave at the interface
What does an object look like if it absorbs all light?
Opaque
What does an object look like if all light is transmitted through it?
Transparent
What happens to light if it travels through a material less dense?
It speeds up and bends away from the normal
What happens to light if it travels through a material more dense?
It slows down and bends towards the normal
What is specular reflection?
Reflection from a smooth, flat surface eg. Reflection off a mirror
What is diffuse reflection?
Reflection off a rough surface
What is the opposite of upright?
Inverted
What is the opposite of magnified?
Diminished
What is a real image?
An image that can be projected onto a screen
What is a virtual image?
An image that looks like it is in one place, but is not in reality. Eg. A reflection on a mirror
What is the order of colours in the visible light spectrum?
Red
Orange
Yellow
Green
Blue
Indigo
Violet
Which colour has the longest wavelength?
Red
Which colour has the shortest wavelength?
Violet
Which colour has the highest frequency?
Violet
Which colour has the lowest frequency?
Red
When a particle absorbs radiation, what increases?
It’s internal energy
How can we see blue?
A spectrum of white light will hit the object, all the colours of the visible light spectrum will be absorbed, apart from blue which is reflected into our eyes
If an object absorbs all light, what colour will it appear?
Black
How would you filter the colour of a ray of white light?
You would use colour filters
What happens when the angle of incidence is smaller than the critical angle?
Refraction
What happens when the angles of incidence is larger than the critical angle?
Total internal reflection
What is the critical angle?
The angle of incidence where the angle of reflection will be 90°
What happens when a light ray hits a concave lens at an angle?
It diverges
