Test 1 Y9 Flashcards
(43 cards)
What is the function of the cornea
It controls how big your iris can get
What is the function of the iris
focus’ on what you can see
What is the function of the pupil
Like a hole that lets light into the lens and retina
What is the function of the lens
The lens is able to adjust to form a picture for us to see
What is the function of the retina
It contains 130 million light sensitive cells
What is the function of the optic nerve
It carries the signal from the eye to the brain
What happens when a ray of light enters a see through block at 90°
The light won’t change direction
What happens when a ray of light enters a see through block at any angle other than 90°
The light changes direction
What happens when light moves from air to glass
It slows down
What happens when light moves from glass to air
It speeds up
How do lenses work
Lenses work because their curved surface refracts the light and bends it
If both sides of a lens are pointed out what is it
A converging lens
If both sides of a lens are pointing in what is it
A diverging lens
When a light ray passes through a convex/ converging lens what happens
They crossover
When light passes through a diverging/concave lens what happens
They spread out
White light is split into the the colours of a rainbow through a prism what is this called
Dispersion
How does dispersion happen
The violet light slows down and the red light speeds up
What is the order of the em spectrum from high to low
Gamma
X-ray
UV
Visible
Infrared
Microwave
Radio
What does em stand for
Electro magnetic
What are the dangers and uses of gamma
They can pass through bones or teeth and cause cancer but also heals cancer
What are the dangers and uses of X-ray
They can cause blocked blood vessels and bone cancer but are very useful in hospitals to check for Brocken bones and pregnancy
What are the dangers and uses of uv
These can cause skin cancer and sunburn
What are the dangers and uses of visible light
It helps us see our surroundings but can cause sunburn if excessive
What are the dangers and uses of infrared
IR is used for cooking and remote controls but can cause damage to the skin
