Reflection
What happens to light when it reflects off a mirror?
it bounces off
What is refraction?
The bending of light as it passes from one medium to another
What does a ray diagram show?
The path light takes through or around an object
Which type of lens is thicker in the middle: converging or diverging?
converging lens
What optical device uses lenses to help people see clearly?
name the line drawn at 90 degrees to the surface of the ray?
the normal
why does light refract when entering a different medium?
because speed changes
What is the principle axis in a ray diagram?
The straight line passing through the centre of a lens or mirror
which type of mirror curves inward like a cave?
concave mirror
What natural phenomenon occurs when sunlight is refracted and dispersed by raindrops?
A rainbow
According to the law of reflection, how does the angle of incidence (incoming) compare to the angle of reflection?
They are equal
When light travels from air into plastic, does it bend towards or away from the normal?
towards the normal
it passes through the focal point
What kind of image is usually produced by a plane mirror?
A virtual, upright image
What type of mirror is commonly used as a vehicle side mirror to provide a wider field of view?
A convex mirror
A light ray strikes a mirror at an angle of incidence of 35 degrees, What is the angle of reflection?
35 degrees
Which medium is optically denser: air or glass?
Glass
How many principle rays are usually needed to locate an image in a ray diagram?
two (three for accuracy)
How does a Fibre-optic cable transmit light over long distances?
by repeating total internal reflection
A ray reflects from two perpendicular mirrors. By how many degrees has its direction changed overall?
180 degrees (in travles back in the opposite direction)
Explain why a straw appears bent when placed in a glass of water?
Light refracts as it moves between water and air, making the submerged part appear shifted
In a converging lens (convex) ray diagram, an object is placecd exactly at the focal point (f). What happens to the light rays after they pass through a lens?
The rays emerge parallel to each other and do not meet, so the image is not formed
Why are concave mirrors used in makeup mirrors and medical mirrors?
They can produce enlarged upright images when the object is close to the mirror
Explain how a camera forms an image?
think: lens, sensor and focus and type of image
A converging lens refracts light rays and focuses them onto a sensor to form a real image