Created by Jamari, S.Pd.
CAPASITORCAPASITOR
Source : Haliday-Resnick-Walker
Adaptif
CAPASITOR
A capasitor consist of two parallel conducting plate, each of area A, that separated by dielectric material/isolator/ vaccum
A capasitor consist of two parallel conducting plate, each of area A, that separated by dielectric material/isolator/ vaccum
Between two plate are related with different electric potential V. Each plate carries equal amount of charge. One plate carries positive charge and the other caries negative charge.
Between two plate are related with different electric potential V. Each plate carries equal amount of charge. One plate carries positive charge and the other caries negative charge.
Source: Haliday-Resnick-Walker
Dielectric materials
Area =A
Adaptif
CAPASITOR
Characteristic of capasitor Can save electric energy
without chemistry reaction Can’t be passed by DC
electric current, but can be passed easily by AC electric current
If it is related with different electric potential, each plate carries equal amount of charge. One plate carries positive charge and the other caries negative charge.
Hal.: 3 Characteristic of capasitor
Symbol of capasitor
+V
+Q -Q
Adaptif
CAPASITANCE of CAPASITOR
Capasitance of capasitor (C) shows the amount of charge in each plate, if both of them have different electric potential 1 volt
Hal.: 4 Capasitance of Capasitor
+V
+Q -Q
V
V
QC Q = the amount of charge in each plate
V = different electric potential between two plates (Volt)C = Capasitance of capasitor (Farad = F )
AdaptifHal.: 5 Capasitance of Capasitor
vaccum
Area =A
V
QC
d
xAεC o
C = capasitance of capasitor (Farad= F)
d = distance (meter)
A = surface area (meter 2 )
o = permitivitas udara atau ruang hampa
( 8.854 187 82 · 10-12 C/vm )
dAεQQ
Exd
QC
o
x
CAPASITANCE of CAPASITOR
AdaptifHal.: 6 Capasitance of Capasitor
Dielectrics materials
Area =A
d
εxAC
= permitivitas bahan dielektrik (C/vm )
K.εε o
K = dielectric constanta (vaccum, K = 1 )
CAPASITANCE of CAPASITOR
Adaptif
CAPASITOR
Series circuit
Hal.: 7 Series circuit
+V
+Q1-Q1 +Q2
-Q2
1. Capasitance of capasitor (Cg ), Capasitance of 1st capasitor (C1), Capasitance of 2nd capasitor (C2) is:
2. The charge that is kept in circuit= the charge in each capasitor. Q = Q1 + Q2 dan Q1 = Q2
3. Electric potential(V), potential at 1st capasitor (V1 ) and 2nd capasitor (V2 ) is:V = V1 + V2
1. Capasitance of capasitor (Cg ), Capasitance of 1st capasitor (C1), Capasitance of 2nd capasitor (C2) is:
2. The charge that is kept in circuit= the charge in each capasitor. Q = Q1 + Q2 dan Q1 = Q2
3. Electric potential(V), potential at 1st capasitor (V1 ) and 2nd capasitor (V2 ) is:V = V1 + V2
21g C
1
C
1
C
1
Adaptif
Circuit of Capasitor
Series Circuit
Hal.: 8 Series Circuit
+V = 6 volt
+Q -Q +Q -Q
C1 = 2 F C2 = 3 F
Example:Example:
1. Kapasitance of capasitor :
Cg = 6/5 = 1,2 F
2. The charge in the circuit = 1,2 F x 6V = 7,2 C 1st capasitor = 7,2 C 2nd capasitor = 7,2 C
3. Electric potential: 1st capasitor = 3,6 V 2nd capasitor = 2,4 V
1. Kapasitance of capasitor :
Cg = 6/5 = 1,2 F
2. The charge in the circuit = 1,2 F x 6V = 7,2 C 1st capasitor = 7,2 C 2nd capasitor = 7,2 C
3. Electric potential: 1st capasitor = 3,6 V 2nd capasitor = 2,4 V
6
5
6
23
3
1
2
1
C
1
g
Adaptif
Circuit of Capasitor
Paralel Circuit
Hal.: 9 Paralel Circuit
+V
+Q1-Q1
+Q2-Q2
1) Potential at 1st capasitor (V1), 2nd capasitor (V2) and at the source potential (V) is V1 = V2 = V
2) The charge that is kept in the circuit is Q = Q1 + Q2
3) Capasitance of union of capasitor is: Cg = C1 + C2
Adaptif
Circuit of Capasitor
Paralel Circuit
Hal.: 10 Paralel Circuit
1. Each capasitor has same potential, then we get V1 = V2 = 6 volt
2. Capasitance of capasitor is Cg = C1 + C2 = 2F + 3F = 5F
3. The charges that are kept in the circuit are:
Q = Cg xV = 5F x 6V = 30CQ1 = C1 x V = 2Fx6V = 12C
Q2 = C2 x V = 3Fx6V = 18C
Example: Example:
+
+Q1-Q1
+Q2-Q2
C1 = 2 F
C2 = 3 F
V = 6 volt
Adaptif
Electric energy that is kept at capasitor The Graphics of relation the voltage (V) with the
charges in capasitor (Q)
Hal.: 11 Electric Energy in Capasitor
V(volt)
Q(Coulomb)Electric energy in capasitor that has charge Q = surface areaunder curva graphics Q-V (the hatching ).
Q
V
QV2
1W
Adaptif
Electric energy that is kept at capasitor
Hal.: 12 Electric Energy in Capasitor
(CV)V2
1W
+V
A capasitor has capasitance C is connected with voltage V.
Cbecause Q = C.V, so
2CV2
1W
W = electric energy in capasitor (Joule)
Q = Charge in capasitor (Coulomb)
C = Capasitance of capasitor (farad)
V = Voltage between parallelplate capasitor (Volt)