Waves Flashcards
How are stationary waves formed?
They are formed when 2 progressive waves with the same amplitude , frequency and phase difference travelling in opposite directions interfere with each other
How long is a wavelength in Pi
2Pi
Equation for fringe separation W=fringe separation D=distance from slits to screen s=slit spacing wavelength arrange for slit spacing to be the subject
s=(wavelength x D)/w
How are bright fringes formed
Light from one slit reinforces light from other slit
How are dark fringes formed
Light from one slit cancels light from other (light waves are 180 degrees out of phase
Equation for wavelength with c,f,λ
c/f=λ
The equation for fringe spacing
λD/S=W
What is a node?
This is points of no displacement where the nodes remain in the same position. Particles at those points are not vibrating at all and they have no energy.
The equation for Diffraction Grating
d sin(θ)=nλ
The refractive index of air
1.000277 or 1
The equation for the refractive index of a substance
n=C/Cs
Total internal reflection: sinθc = ???
n2/n1 where n2>n1
The refractive index of Diamond
2.417
Snell’s law for refraction of a boundry
n1 sinθ1 =n2 sinθ2
What are coherent sources
The light emitted is in constant phase difference and same frequency
How do you reinforce a fringe
Have wavelength arrive in phase with monochromatic light
E.G. π,2π,3π
How do you cancel the path difference
May light 180 degrees out of phase
E.G. π/2, 2π/3, 3π/4
The refractive index of Diamond
2.417
A light ray is directed into a glass block that has a refractive index of 1.5 at an angle of incidence of 40°. Calculate the angle of refraction.
sin−1(sin40/1.5)
What is the diffraction grating equation
Wavelength
Diffraction grating=d
d x sin(theta)=n x wavelength
How to calculate number of slits per metre on the grating
d = diffraction grating
N = number of slits per metre
N=1/d
sin(i)/sin(r) = C/?
C/Cs