P14: Light Flashcards
What is the law of reflection?
The angle of incidence = The angle of reflection
What is the difference between a real and virtual image?
A real image is an image formed by a lens that can be projected onto a screen.
A virtual image cannot be projected onto a screen as it is seen in a lens or a mirror.
What is refraction?
The change of direction of waves due to a change in substance/medium
What causes refraction in a wave?
When waves change the substances they are in at an angle, part of the wave enters the new substance before the other part. This causes one part of the wave to speed up or slow down before the other part of the wave, causing the wave to change direction.
What are the refraction rules?
If a light ray moves from a less dense medium to a denser medium, they move towards the normal.
If a light ray moves from a more dense medium to a less dense medium then they move away from the normal.
What is the difference between red light and violet light?
They have different wavelengths so in result a different frequency
What is white light made of?
All the colours on the spectrum
How do colour filters work?
Colour filters work by absorbing certain wavelengths and transmitting other wavelengths
How do transparent objects work?
They transmit all light through the object
How do translucent objects work?
Light is transmitted, but is scattered or refracted as it does
How do opaque objects work?
Light does not pass through, instead the object either absorbs all light that reaches it or reflects it
What are the 2 types of lenses?
Convex and concave lenses
How do convex lenses work?
Convex lenses make parallel rays converge towards the centre of the lens
How do concave lenses work?
Concave lenses make parallel rays diverge away (spread out) from the centre of the lens
What is the equation for magnification?
Magnification = Image height / object height
