P3: Light Waves, Lenses Flashcards
Theories of light
- wave theory
- particle theory
- quantum theory
what is the quantum theory of light?
light is both particle-like as well as wave-like in nature
in the particle theory each (1)_________ is a (2)___________ of energy known as a (3)___________.
- wave pulse
- packet
- photon
what is a photon
a packet oe electromegnetic energy
general wave equation
1 - medium one
2- medium two

What is an angle of incidence?
The angle between the incident ray and the normal.
What is an angle of reflection?
The angle between the reflected ray and the normal.
what are the laws of refraction?
- The angle of incidence equals the angle of reflection.
- the ratio sin(i)/sin(r) is a constant for a pair of media
What are the laws of reflection?
- The angle of incidence equals the angle of reflection.
- the incident ray, reflected ray and the normal at the point of incidence are all on the same plane
What is a plane mirror?
A perfectly flat mirror.
What is a virtual image?
An upright and laterally inverted image.
How is a real image formed?
Focusing light onto a screen.
What is refraction?
The change of direction of waves when they travel across a boundary between 2 media of different optical densitities
What happens to a light ray when it travels from air to glass?
The angle of refraction is less than the angle of incidence. The ray travels towards the normal.
What happens to the speed of a light ray when travelling from glass into air?
it increases
What is diffraction?
The spread of waves when passing through a gap or round the edge of an obstacle.
How does the width of the gap effect the diffraction of waves?
The narrower the gap is, the greater the diffraction.
Why can radio and TV reception be poor in hilly areas?
If the radio waves do not diffract enough, the waves won’t reach the aerial on a house.
How does diffraction effect optical imaging?
If light diffracts too much, the image is of poor quality.
diffraction does not affect the (1)___________, (2) ______________, (3)_______________ , or the (4)________________ of light
- speed
- wavelenght
- period
- frequency
what is interference
phenomenon which occurs at a point where 2 or more waves superpose on each other to produce a combined vibration of amplitude lesser or greater any of the individual waves
constructive interference
phenomenon which occurs at a point where 2 or more waves superimpose in phase to produce a combined vibration of amplitude greater any of the individual waves
constructive interfrence occurs where 2 or more (1)_________ or (2)________ of transverse waves meet , or where 2 or more (3)_________ or (4)__________ of (5)__________ waves meet
- crest
- troughs
- compressions
- rarefractions
- longitudinal
destructive interference occurs where (1)_________ meets (2)________ of transverse waves meet , or (3)_________ meet (4)__________ of (5)__________ waves meet
- crests
- troughs
- compressions
- rarefractions
- longitudinal


















