P14 - Light 2️⃣✅ Flashcards
What is a plane mirror?
One that is straight and not curved
What is the angle of incidence?
The angle between the incident ray and the normal line
What is the angle of refraction?
The angle between the refracted ray and the normal
What is a concave lens?
A lens that diverges rays outwards
What 3 key words would discribe an image produced by a concave lens?
- Virtual
- Upright
- Enlarged
What is a convex lens?
A lens that converges rays onto one focal point
What 3 key words would discirbe an image produced by a convex lens?
- Real
- Inverted
- Diminished
What are common uses for concave lenses?
- Binoculars
- Glasses ( myopia)
What is a common uses for convex lenses?
- Glasses (Hyperopia)
What is diffuse relfection?
A reflection of a ray from a rough surface and therefore the light rays are scattered in differnet directions
What is specular reflection?
A reflection of a ray from a smooth surface and therefore each light ray is reflected in the same, single direction
What is focal length?
The distance from the centre of a lens to the point where light rays parallel to the prinicpal axis are foucsed/ appear to diverge from
What is the equation for magnification?
Magnification = Image height ÷ object height (IAM TRIANGLE)
What is the normal line?
A straight line through a surface or boundary perpendicular to the surface or boundary
What does it mean when an object is opaque?
That light cannot pass through it
What does it mean when an object is transluscent?
That some light can pass through it
What does it mean when an object is transparent?
All light can pass through it
List the 3 pirmary colours of light
- Red
- Blue
- Green
List the 4 secondary colours of light
- Cyan
- Magenta
- Yellow
- White
How do objects appear coloured?
Certain objects reflect only certain colours of light and will absorb all the other colours. e.g. Grass is green because it reflects green light and absorbs all the other colours on the spectrum
What does it mean in terms of light when an object appears black?
That it absorbs all the colours on the spectrum
What does it mean in terms of light when an objects appears white?
That it reflects all the colours on the spectrum
What is a real image?
An image formed when real light rays corss that can therefore also pe projected
What is a virtual image?
An image formed when ‘fake rays’ are etrapolated backwards and therefore cross. Because they are not real rays and dont actually ever cross, the image cannot be projected onto a screen
Order how you would draw a ray diagram for a convex lens
- 4
- 5
- 1
- 3
- 2
What is refraction?
When a wave changes direction due to a change in speed when meetign a boundary at an angle
What do you do differently when drawing a ray diagram for a concave lens?
After drawing in the rays through the centre of the lens and parallel to the principle axis until the lens - you would take the parallel ray and extrapolate it backwards by joining it back wards to the focal point that would be on the left of the lens by the image. Where this newly drawn line meets the ray that goes through the middle of the lens is where the virtual image would be formed.
What type of wave are electromagnetic waves?
Transverse, so travel perpendiular to the direction in which the wave transfers energy
What is a Charge Coupled Device (CCD)?
A charged coupled device (CCD) absorbs infrared radiation to produce an image. Each pixel in the CCD detects the infrared radiation and the data can be processed using a computer.
What is another word for a convex lens?
A converging lens
What is another word for a concave lens?
A diverging lens
What lens is this the short hand symbol for?
A convex lens (converging)
What lens is this the short hand symbol for?
A concave lens (diverging)
Label this ray diagram for a refracted ray
If a light ray enters a more dense medium as it refracts it will bend ____________ the normal
If a light ray enters a more dense medium as it refracts it will bend towards the normal
If a light ray enters a less dense medium as it refracts it will bend ____________ the normal
If a light ray enters a less dense medium as it refracts it will bend away from the normal
