E = electric field ( N/C) F = static electricity charge

Static Electricity
Sumber Gambar : site:
gurumuda.files.wordpress.com
Created by Jamari, S.Pd.
Sumber Gambar Fisika SMK Teknologi,
Direektorat SMK
Phenomenons 0f Static electricity
Hard ruber stick, a Stick of glass or a
ruler of plastic is scrubed in cloth
Phenomenons 0f
Static electricity
Plastic ruler is scrubed
in dry hair
Iron nyilon cloth
and all that
Hal.: 2
Phenomenons of Static electricity
Created by Jamari, S.Pd. Adaptif
Electric Charge
 Anything is scrubed in different thing with the result that static
electricity, so thing is called containt electric charge.
Two plastic rulers and two glass sticks are scrubed by drugget so each are
be charge
The two of ruler mutual refuse to
averse
Sumber Gambar Modul Listrik Statis,
Direktorat Pendidikan Menengah
Kejuruan
Hal.: 3
Phenomenons of Static electricity
Created by Jamari, S.Pd. Adaptif
Electric Charge
The two of glass sticks mutual
refuse to averse
A plastic ruler and a glass
stick are trade-offs
Hal.: 4
Phenomenons of Static electricity
Created by Jamari, S.Pd. Adaptif
Electric Charge
Everything that is pulled glass so pussed away plastic ruler
Everything that is pussed away glass so pulled plastic ruler
positive
charges (+)
The Phenomenons
show there are two
kinds of electric
charges
negative
charges (-)
Franklin choose electric charges in glass as positive
charges, and electric charges in plastic as negative
charges. On time the treaty still are used
Hal.: 5
there are two kinds of electric charges
Created by Jamari, S.Pd. Adaptif
Electric Charge
Have symbol Q or q
SI unit electric charge is Coulomb (C)
Electric Charge
Elementary charge is 1,6 x 10 -19 C
The charge on a single electron
is -1.6 x 10 -19 Coulomb
The charge on a single proton is
+1.6 x 10 -19 Coulomb
Hal.: 6
Electric Charge
Created by Jamari, S.Pd. Adaptif
Coulomb’S Law
F12 = force at particle 1 by particle 2 ( Newton )
F 21 = force at particle 2 by particle 1 (Newton )
r
= the distance of separation between the two
objects (meters )
k
= a proportionality constant known as the
Coulomb's law constant
is dependent upon the medium that
the charged objects are immersed in
k
Hal.: 7
In the case of air & vacuum , the
value is approximately 9,0 x 109
Nm2 / C2
Coulomb’S Law Class XII
Created by Jamari, S.Pd. Adaptif
Coulomb’S Law
Value k (constanta ) besides air or vacuum
k
1
4
  K . o

o
= permitivitas a media
= permitivitas of air or
vacuum
K
Hal.: 8
= dielectrik constanta
For air or vacuum
K=1
Hukum Coulomb
Created by Jamari, S.Pd. Adaptif
Hukum Coulomb
=F
F
Hal.: 9
k
1
4
Hukum Coulomb
  K . o
Created by Jamari, S.Pd. Adaptif
Hukum Coulomb
Contoh soal
On the air found two electricity charge 10 μC and 40 μC and apart in
distance 20 cm
a. How much is big load second interaction force?
b. When does second load laided at a medium that has dilelectric
constant 3, how much is force that undergone by 40 μC ?
Hal.: 10
Hukum Coulomb
Created by Jamari, S.Pd. Adaptif
Hukum Coulomb
Penyelesaian :
Hal.: 11
a.
Hukum Coulomb
Created by Jamari, S.Pd. Adaptif
Hukum Coulomb
b.
= 30 N
Hal.: 12
Hukum Coulomb
Created by Jamari, S.Pd. Adaptif
The electric field
 An electric field is said to exist in the region of space around a
charged object. When another charged object enters this electric field,
an electric force acts on it.
A convenient way of
visualizing electric field
patterns is to draw lines
that follow the same
direction as the electric
field vector at any point.
These lines, called electric
field lines
Hal.: 13
Medan Listrik di sekitar muatan
Created by Jamari, S.Pd. Adaptif
Electric field E
E
Electric field lines penetrating two
surfaces. The magnitude of the
field is greater on surface A than
on surface B
Hal.: 14
The number of lines per
unit area through a
surface perpendicular to
the lines is proportional
to the magnitude of the
electric field in that
region
Sumber : Halliday-Resnick-Walker
The magnitude of the electric field
Created by Jamari, S.Pd. Adaptif
Magnitude of the Electric Field
the electric field E at a point in space is defined as the electric
force F acting on a positive test charge q placed at that point
divided by the magnitude of the test charge
E
.
E
Elctric field
Hal.: 15
F
q
belong
Vector
QUANTITIES
Kuat Medan Listrik
E = electric field ( N/C)
q = electricity charg
(Coulomb)
F = static electricity charge
(Newton)
it has value
it has direction
Created by Jamari, S.Pd. Adaptif
Electric Field direction at a Point
 Electricity field intensity direction is unidirectional
and correlating to squeez with the electric force F
acting on a positive test charge q placed at that point
divided by the magnitude of the test charge
B
.
E
Hal.: 16
+
A
.
E
Arah kuat medan listrik
Created by Jamari, S.Pd. Adaptif
Electric Field aroud negative electricity
Charge
B
.
E
Hal.: 17
-
A
.
E
Arah kuat medan listrik
Created by Jamari, S.Pd. Adaptif
Electric Field in area between two
electricity charge
At point C doesn’t has
electric field
Hal.: 18
Medan Listrik
Created by Jamari, S.Pd. Adaptif
Electric Field in area between two
electricity charge
There is a point
between two
electricity charge
that has
strongest Electric
Field
Hal.: 19
Medan Listrik
Created by Jamari, S.Pd. Adaptif
The Eletric Field Around
Electricity Charge
 The electric field at a point, such as A, that has distance of electrical
charge particale as Q
In order to determine electric filed at
point A we put electricity charge as q
at point A.
+
Q
E=
Hal.: 20
r
F
q
=
qxQ
k 2
r
q
A
.
E=
E
F
q
Q
= k
r
Q
2
Kuat Medan Listrik di sekitar muatan titik
E= k
r2
Created by Jamari, S.Pd. Adaptif
Electric Flux
Field lines representing a
uniform electric field
penetrating a plane of
area A perpendicular to
the field.
The electric flux E
through this area is
equal to EA
=ExA
Sumber : Haliday Resnick, 745
Hal.: 21
Fluks Listrik
Created by Jamari, S.Pd. Adaptif
Electric Flux
When area A is
at an angle 
to the field:
 = E x A cos 
Sumber : Haliday Resnick, 745
Hal.: 22
Fluks Listrik
Created by Jamari, S.Pd. Adaptif
Gauss’s Law
The net flux through any
closed surface surrounding a
point charge q is given by q/o
Karl Friedrich Gauss
(1777–1866)

Hal.: 23
Hukum Gaus
Q
o
Created by Jamari, S.Pd. Adaptif
Gauss’s Law
the net electric flux through a
closed surface that surrounds
no charge is zero
 0
Hal.: 24
Hukum Gaus
Created by Jamari, S.Pd. Adaptif
Hukum Gaus
If E is perpendicular to area A, so
=ExA
=
Q

o
Q = electrical charge in closed
surface ( Coulomb )
ExA=
E=
Hal.: 25
Q

o
Q

o
E=
A

 = charge density ( C/m2 )


o
o=
permitivitas of air or vacuum
= 8,85 x 10-12 C2 N-1m-2
Hukum gaus
Created by Jamari, S.Pd. Adaptif