وزا ر ة التربية التوجيه الفني العام للعلوم
DESCRIPTION
المركز الإقليمي لتطوير البرمجيات التعليمية. الفيزياء للصف الثاني عشر العلمي. وزا ر ة التربية التوجيه الفني العام للعلوم. العروض التقديمية. عرض تقديمي بعنوان:. - المكثفات Capacitors. Capacitors. A uniform electric field is an electric field in which the - PowerPoint PPT PresentationTRANSCRIPT
التربية روزا ة العام الفني للعلومالتوجيه
اإلقليميالمركزالبرمجيات التعليمية لتطوير
العروض التقديمية
Capacitorsالمكثفات -بعنوان تقديمي :عرض
الفيزياء للصف الثاني عشر العلمي
A uniform electric fieldis an electric field in which the
field strength does not vary. This givesa constant force on any charge that
exists in the field.
A uniform electric fieldis an electric field in which the
field strength does not vary. This givesa constant force on any charge that
exists in the field.
electric potential difference
= work per unit charge = force x distance per unit charge = force per unit charge x distance = electric field strength x distance
V = Ed V = Ed E = V/d, with units of volts/meter
CapacitorCapacitora device that stores charge
made of two conductors separated by an insulator
The amount of charge that acapacitor can store depends on:1. area of conducting surface2. distance between the conductors3. type of insulating material
link
Capacitancethe ratio of charge to potential difference
C = Q/V Q = CV
The SI unit of capacitanceis the Farad, F, named inhonor of Michael Faraday.
One Farad of capacitance means thatone Coulomb of charge may be stored
in the capacitor for each Volt of potential difference applied.
One Farad of capacitance means thatone Coulomb of charge may be stored
in the capacitor for each Volt of potential difference applied.
Capacitor CircuitsSeries
1. reciprocal of the total capacitance is the sum of the reciprocals of the separate capacitors
1/CT = 1/C1 + 1/C2 + 1/C3 + ...
2. charge is the same on each capacitorQT = Q1 = Q2 = Q3 = ...
3. total potential difference is the sum of each
VT = V1 + V2 + V3 + ...
In other words, in a series circuit,capacitance adds as reciprocals,
charge stays the same,and voltage adds.
C1
C2
C3
E = 12 V
CT =
VT =
QT =
C1
C2
C3
C,mF
V,V
Q,mC
12
10
15
C1
C2
C3
E = 12 V
CT = 4.0 mF
VT = 12 V
QT = 48 mC
C1
C2
C3
C,mF
V,V
Q,mC
12
10
15
48
48
48
4.0
4.8
3.2
Parallel1. total capacitance is the sum of each separate capacitor CT = C1 + C2 + C3 + ...
2. total charge is the sum of the charges on each separate capacitor
QT = Q1 + Q2 + Q3 + ...3. potential difference is the same across each capacitorVT = V1 = V2 = V3 = ...
In other words, in a parallel circuit,
capacitance and charge add, but voltage stays the same.
C3
E = 12 V
CT =
VT =
QT =
C1
C2
C3
C,mF
V,V
Q,mC
8
10
4C2
C1
C3
E = 12 V
CT = 22 mF
VT = 12 V
QT = 264 mC
C1
C2
C3
C,mF
V,V
Q,mC
8
10
4C2
C1
12
12
12
96
120
48
Capacitors are often used in conjunctionwith resistors in simple circuits that arecalled RC Circuits.
Click here and here to view computersimulations of this type circuit.
Explore this link to learnmore about capacitors.