define displacement (waves)
The distance from the equilibrium positions
define amplitude
max displacement
Define wavelength
The minimum distance between two points in phase on adjacent waves
Define time period of oscillation
the time take to for a wave to complete one oscillation
frequency definition
the number of wavelengths passing a point per unit time
wave speed
the distance travelled by the wave per unit time
wave equation
v=f x lamda
define phase difference
the difference between displacement of particles on a wave
what is the phase difference when two particles in phase
0 or 2pi radians
what is the phase difference when two particles in anti-phase
pi radians
When does reflection occur
reflection occurs when a wave changes direction at a boundary between two different media
what is the law of reflection
angle of incidence + angle of reflection
when does refraction occur
when a wave changes direction as it changes speed form one media to another
If water is shallower the speed of the waves are ____.
slower
What is diffraction?
when waves pass through a gap or round an obstacle and spread out
what is polarised?
When a wave’s vibration is confined to one plane of oscillation
Intensity=
Power/Area
You can polarised electromagnetic waves using polarisers
This means only waves with a certain orientation can pass through
The refractive index
speed of light in vacuum/ speed or light in a material
What is the Snell’s law?
n1sin(x1)+n2sin(x2)
Total internal reflection
theta is greater than the critical angle
sin of the critical angle=
1/refractive index
super position
when two waves of the same type passing through each other
Define Coherence
Waves emitted from two sourcing having constant phase difference and the same frequency.
what does each of the symbols mean in
lamda= ax/D
a: slit separation, D: distance fro source to screen, x: separation between light and dark and screen
What is node
a Point of 0 displacement, 0 intensity and 0 amplitude on a stationary wave
What is an antinode
a Point of max displacement, max intensity and max amplitude on a stationary wave
A stationary wave in a coloumn starts and stops when in a one end closed and a both ends open
One open: Starts in middle on one end and top on open
Both open: Starts and ends on edges of tube
what does the symbols stand for in:
E=hc/lamda
Energy of photon= Planck’s constat x Frequency
One electronvolt is
the energy transferred when an electron moves through a pd of one volt
The photoelectric effects
When the electromagnetic radiation hits the surface of a metal causes electrons to be emitted
Define work function ( circle with line)
The minimum energy required to free and electron from the surface of a metal
what do the symbols mean of : hf= (circle line) + Ekmax
Energy of a photon= Work function + max KE of emmited electron
What is used to diffract electrons
polycrystaline graphite
