P14 - Light Flashcards
Reflection consists of?
Light waves
Frequency, speed & wavelength of
reflected and incident waves?
Same, same, same
Normal?
Line perpendicular to mirror
Virtual image?
Can’t be projected onto a screen
Real image?
Can be projected onto a screen
Specular reflection?
surface and direction?
Reflection from a smooth surface
Parallel light rays reflected in 1 direction
Diffuse reflection?
surface and direction?
Reflection from a bumpy surface
Light scattered in different directions
Angle of incidence?
Angle between incident ray and normal ray
Refraction?
Change of direction of waves when they travel across a boundary from one medium to another
Law of reflection?
angle of incidence = angle of reflection
What happens to angle of refraction when light rays refract when they travel from air into glass?
angle of refraction is less then the angle of incidence
What happens to angle of refraction when light rays refract when they travel from glass into air?
angle of refraction is more than the angle of incidence
What happens to wavelength of light as you go down the spectrum from violet to red?
wavelength increases
D. Transparent?
lets all the light that enters it pass through it and doesn’t scatter or refract the light inside the object
D. Translucent?
lets light through but scatters or refracts the light inside it
D. Opaque?
absorbs all the light that reaches it. light that hits it is either reflected. scattered at the surface or absorbed by the object - no light passes all the way through - cant see through it
Colour of the surface of an object depends on…
pigments of the surface materials and wavelengths of light that the pigments absorbs
Convex lens?
(or converging) focuses parallel rays at a point called the principle focus
Concave lens?
(or diverging) makes light rays spread out (diverge) so they focus on the principle focus of the lens
What lens is used to correct short sight?
diverging / concave
What lens is used to correct far sight?
converging / convex
E. Magnification?
image height / object height
Real image is formed by…
a convex lens is the object is further away than the principal focus
Virtual image is formed by…..
a convex image is the object is nearer then the principal focus
Position and nature of image formed by lens depends on… (2)
- focal length of lens
- distance from object to the lens
What lens does a camera contain?
convex lens used to form real images of objects
Image formed by a concave lens is always…
virtual, upright and smaller then object
Real image formed by a convex lens is always…
real, inverted and enlarged then object
Virtual image formed by a convex lens is always…
virtual, upright, larger then object
