Summary - Unit 5 - Waves and Particle Nature of Light

MS
transverse (90) direction propagation
%
-




displacement is normal to the wave
of




#hamit distance
am=4
wavelength ,
↑
=4
time period ,
T
times




fX
Wavelength ,
#
m




= L
f =
time period ,
s


wave speed mst , frequency ,
Hz
frequency ,
Hz




phase
-

describes a part of the oscillation at a point
200
a




superposition the resultant displacement at point equals the
-

wave a sum of


the displacements of all waves incident at that point



if the path difference between two waves is ni the waves interfere

BIG in
constructively : the amplitude is ,
the waves are phase




if the path difference between two waves is (n + 2) X the waves



interfere destructively : the
amplitude is small ,
the waves are in antiphase



constructive interference destructive interference
W
-11 H
-




standing waves
-
two waves of the same
type travel in opposite directions
and superpose forming a series of
des
and antinode a
-


zero displacement
↓
↑sa A




k*
maximum displacement



IX

, fixed it has
fundamental frequency when
string is at both ends
-


a



- its lowest
frequency ,
but biggest amplitude


Wave front-made up of all the points of the wave that are in phase


diffraction -


when a wavefront passes through an aperture and
changes shape




#D will spread our more
- it
is smaller or




time
wave has
path difference
- n = 2


diffraction grating & n = 1
atto
* & -n = 0

Sz
laser beam -n = 1



-n =
2




sinOn = sit
Light
itself
from

causing
a
single
a
slit

central
will


bright
interfere

Gringe
with



separation surrounded
by alternate
bright and dark


fringes

construction point
Huygen's treated
-


on a
wavefront be as
every can a




point source of a
secondary wavelet


& v


·
incident wave
-
Y
Laws of reflection i)

oi =
r
F r(
&
reflected wave


·
incident , normal , reflected are all on the same
plane