I can calculate the
energy :
(and quantities a
momentum associated with
electromagnetic waves devid
Avina - EB =
if theres a voltage : a current there
7
is an electric field .
At
A
changing magnetic flux creates an induced voltage
Voltage- drives current
two types of electric fields
Electrostatic : comes from charges like batteries
Induced electric field : Comes from a
changing magnetic field , field lines form closed loops
changing B field - creates E field- causes voltage - causes current
if you see light, electromagnetic waves , energy/momentum radiation =
L02
an accelerating electric charge must produce electromagnetic waves
why/how is light an
electromagnetic wave?
A changing electric field creates an
magnetic field Vice Versa
↳
they keep making eachothers that lets the disturbance travel through space
that traveling disturbance is light
AC means the current is changing with time.
changing current makes
changing magnetic field
a current in a wire makes a magnetic field around it
.
if flux changes it creates an electric field
magnetic -
,
changing Be E
changing
·
-
changing
e
E-
changing B
·
B and E perpendicular to each other to the direction of waves .
↑
↓
the speed of this self-propogating disturbance C=
·
electric-magnetic
:
so
so
light is an electromagnetic wave .
wave moves in the + X-direction
-
·
E is
=>
in the y-div Cup-down
B is in the z-direction (in out)
·
energy inwaves ? moves forward
↳ energy is in waves so also moves in the X-direction
,
Electromagnetic wares satisfy the wave equation.
, standard wave equation :
energy flows in the same direction the wave moves
V +
=
= C
C is same as V
#Eg
W
= EsMoC XF = =
T
C =
Eo
Bo
Ex =
direction of wave propagation/direction of
short
-
wavelength high =
energy
long wavelength =
low
energy
electromagnetic waves carry
energy
5 : Ex
5
energy flow per area per time
4 How much where its
energy going
Magnitude of s
?
S wim
Lower
:
I
I= S =
A
↳ - tells you energy flow (power per area) ,
not total energy
I
= & since light spreads out in a sphere Area = Yer
>
I
=(3)2
energy :
(and quantities a
momentum associated with
electromagnetic waves devid
Avina - EB =
if theres a voltage : a current there
7
is an electric field .
At
A
changing magnetic flux creates an induced voltage
Voltage- drives current
two types of electric fields
Electrostatic : comes from charges like batteries
Induced electric field : Comes from a
changing magnetic field , field lines form closed loops
changing B field - creates E field- causes voltage - causes current
if you see light, electromagnetic waves , energy/momentum radiation =
L02
an accelerating electric charge must produce electromagnetic waves
why/how is light an
electromagnetic wave?
A changing electric field creates an
magnetic field Vice Versa
↳
they keep making eachothers that lets the disturbance travel through space
that traveling disturbance is light
AC means the current is changing with time.
changing current makes
changing magnetic field
a current in a wire makes a magnetic field around it
.
if flux changes it creates an electric field
magnetic -
,
changing Be E
changing
·
-
changing
e
E-
changing B
·
B and E perpendicular to each other to the direction of waves .
↑
↓
the speed of this self-propogating disturbance C=
·
electric-magnetic
:
so
so
light is an electromagnetic wave .
wave moves in the + X-direction
-
·
E is
=>
in the y-div Cup-down
B is in the z-direction (in out)
·
energy inwaves ? moves forward
↳ energy is in waves so also moves in the X-direction
,
Electromagnetic wares satisfy the wave equation.
, standard wave equation :
energy flows in the same direction the wave moves
V +
=
= C
C is same as V
#Eg
W
= EsMoC XF = =
T
C =
Eo
Bo
Ex =
direction of wave propagation/direction of
short
-
wavelength high =
energy
long wavelength =
low
energy
electromagnetic waves carry
energy
5 : Ex
5
energy flow per area per time
4 How much where its
energy going
Magnitude of s
?
S wim
Lower
:
I
I= S =
A
↳ - tells you energy flow (power per area) ,
not total energy
I
= & since light spreads out in a sphere Area = Yer
>
I
=(3)2
