WAVES
Electromagnetic waves are
oscillating electric and
magnetic fields that
progress through space
without the need for a substance .
vibrating field
generates vibrating magnetic field
generates electric
↳
electric which
a
,
a
vibrating
field and so on .
,
Radio X
light
↳
waves microwaves infrared radiation ultraviolet radiation -
radiation
, , , , , rays ,
gamma
Longitudinal waves are waves in which the oscillation of
particles is
parallel to the wave
propagation .
↳ sound waves
,
primary seismic waves
, compression waves on
slinky .
mooorrroooossrrroooost l '
> l I
,
(
A
'
forward movement to
along other
'
the
causes a
compression wave
pass slinky as the coils
push into each .
A rarefaction
' '
reverse movement causes the coils to move
apart so wave
passes along the
slinky .
Transverse oscillation
waves are waves in which the of
particles is
perpendicular to the wave
propagation .
electromagnetic
↳
secondary string
waves seismic waves waves on or wire .
, ,
today
The movements travel
sideway along the each unaffected part of the pulled sideways when
-
rope ,
as
rope is
next to it
the
part moves
sideways .
POLARISATION
Transverse
plane polarised if the vibrations
stay plane only
'
waves are -
in one .
↳ if vibrations from to another polarised
the
change one
plane ,
the waves are an .
Longitudinal waves cannot be polarised
-
.
of
Plane of
polarisation electromagnetic is defined as the
plane in which the electric field
'
an wave
oscillates .
, > >
'N
ME polarised
"
:
. .
waves
get through
second slit
an
polarised waves
waves
on
rope
at
polaroid right angles
to first polaroid
polaroid
^
7
r a
no
light gets
( ) > . .
- - - -
S through second
L U
polaroid .
v
✓
an
polarised polarised
light
light
If
polarised light passed through transmitted
polarised filter
only
•
an is a
polaroid filter
,
the
light is as the
allows which direction
through light vibrates in a certain
,
according to the
alignment of its molecules .
If transmitted
polarised light passed through two polaroid filters the
light intensity changes if
polaroid
°
ur is one
,
is turned relative to the other one .
polarised light
↳ the
cannot second of
from the first filter
pass through the filter
,
as the
alignment
900 to
molecules in the second filter is at the
alignment in the first filter .
Polaroid reflected water
sunglasses reduce the
glare of
light by glass
"
or .
↳ reflected
light is
polarised , intensity is reduced when it
passes through the
polaroid sunglasses .
TV
signals polarised specific direction
depending orientation of the transmitter
'
are in a on the .
↳
aerial its rods direction
strong signal receiving
must have in the same
:
.
DISH DESIGN
the
bigger the dish the
stronger the
signal it receive radio reflected
by the dish onto the aerial
•
can more waves are
,
.
to because diffracts
bigger reflects smaller focus it the
↳ radio less
a dish the waves a waves .
aligned aerial
needs to be
carefully smaller dish focus radio onto
'
. . more than a to waves .
#
-
.
less diffraction
# -
.
more diffraction
-
spread out
.
-
-
•
less spread out ,
a
more
Large dish
•
narrow beam small dish
.
spread out beam
Electromagnetic waves are
oscillating electric and
magnetic fields that
progress through space
without the need for a substance .
vibrating field
generates vibrating magnetic field
generates electric
↳
electric which
a
,
a
vibrating
field and so on .
,
Radio X
light
↳
waves microwaves infrared radiation ultraviolet radiation -
radiation
, , , , , rays ,
gamma
Longitudinal waves are waves in which the oscillation of
particles is
parallel to the wave
propagation .
↳ sound waves
,
primary seismic waves
, compression waves on
slinky .
mooorrroooossrrroooost l '
> l I
,
(
A
'
forward movement to
along other
'
the
causes a
compression wave
pass slinky as the coils
push into each .
A rarefaction
' '
reverse movement causes the coils to move
apart so wave
passes along the
slinky .
Transverse oscillation
waves are waves in which the of
particles is
perpendicular to the wave
propagation .
electromagnetic
↳
secondary string
waves seismic waves waves on or wire .
, ,
today
The movements travel
sideway along the each unaffected part of the pulled sideways when
-
rope ,
as
rope is
next to it
the
part moves
sideways .
POLARISATION
Transverse
plane polarised if the vibrations
stay plane only
'
waves are -
in one .
↳ if vibrations from to another polarised
the
change one
plane ,
the waves are an .
Longitudinal waves cannot be polarised
-
.
of
Plane of
polarisation electromagnetic is defined as the
plane in which the electric field
'
an wave
oscillates .
, > >
'N
ME polarised
"
:
. .
waves
get through
second slit
an
polarised waves
waves
on
rope
at
polaroid right angles
to first polaroid
polaroid
^
7
r a
no
light gets
( ) > . .
- - - -
S through second
L U
polaroid .
v
✓
an
polarised polarised
light
light
If
polarised light passed through transmitted
polarised filter
only
•
an is a
polaroid filter
,
the
light is as the
allows which direction
through light vibrates in a certain
,
according to the
alignment of its molecules .
If transmitted
polarised light passed through two polaroid filters the
light intensity changes if
polaroid
°
ur is one
,
is turned relative to the other one .
polarised light
↳ the
cannot second of
from the first filter
pass through the filter
,
as the
alignment
900 to
molecules in the second filter is at the
alignment in the first filter .
Polaroid reflected water
sunglasses reduce the
glare of
light by glass
"
or .
↳ reflected
light is
polarised , intensity is reduced when it
passes through the
polaroid sunglasses .
TV
signals polarised specific direction
depending orientation of the transmitter
'
are in a on the .
↳
aerial its rods direction
strong signal receiving
must have in the same
:
.
DISH DESIGN
the
bigger the dish the
stronger the
signal it receive radio reflected
by the dish onto the aerial
•
can more waves are
,
.
to because diffracts
bigger reflects smaller focus it the
↳ radio less
a dish the waves a waves .
aligned aerial
needs to be
carefully smaller dish focus radio onto
'
. . more than a to waves .
#
-
.
less diffraction
# -
.
more diffraction
-
spread out
.
-
-
•
less spread out ,
a
more
Large dish
•
narrow beam small dish
.
spread out beam
