h hukum kirchoff
DESCRIPTION
teknologi elektrikTRANSCRIPT
KIRCHOFF’S LAW
IntroductionIntroduction
Ohm's Law described the relationship between current, voltage, and resistance. These circuits have been relatively simple in nature.
Many circuits are extremely complex and cannot be solved with Ohm's Law. These circuits have many power sources and branches which would make the use of Ohm's Law impractical or impossible.
Kirchhoff’s Law is an important algebraic in solving the currents and voltages of the circuit.
DefinitionDefinition
Node – A point or junction in a circuit where two or more components connect.
Loop – A closed path in a circuit.
Voltage drop – The voltage between any two specific points of an electrical conductor.
Branch – A single or group of components such as resistors or a source which are connected between two nodes.
PartsParts
Kirchhoff can be divided into two parts:
Kirchhoff’s Current Law (KCL)
Kirchhoff’s Voltage Law (KVL)
Kirchhoff’s Current Law (KCL)Kirchhoff’s Current Law (KCL)
Kirchhoff's current law states that the algebraic sum
of the currents entering at a node (i.e., any junction of
wires) equals the sum of the currents leaving that node.
Or the algebraic sum of all currents at any node
in a circuit is equal to zero.
I1
I2 I3
Current In = Current Out I 1 = I 2 + I 3 i.e. I 1 + (- I 2 ) + (- I 3 ) = 0 = 0
Hukum Kirchoff ArusJumlah algebra arus yang memasuki
sebarang titik persimpangan atau nod di dalam litar elektrik adalah bersamaan dengan jumlah algebra arus yang keluar dari titik persimpangan tersebut.
Kirchhoff’s Current Law (ExampleKirchhoff’s Current Law (Example))
I1 = 2A
I5 = 1A
I2 = 5A
I3
I4 = 3A
Refer to the figure above, calculate current I3.
Kirchhoff’s Current Law (ExampleKirchhoff’s Current Law (Example))
Solution
Current entering node : I1 = 2A , I2 = 5ACurrent leaving node : I3 = ?, I4 = 3A, I5 = 1A
Using Kirchhoff’s Current Law, Current entering node = Current leaving node
I1 + I2 = I3 + I4 + I5
I3 = I1 + I2 - I4 - I5
= 2 + 5 - 3 - 1 = 3 A
Kirchhoff’s Voltage LawKirchhoff’s Voltage Law
Kirchhoff‘s Voltage Law states that the sum of voltage
drop is equal to the total source voltage.
Or the algebraic sum of voltage source and voltage
drop in a circuit is zero.
Voltage equation
VS = VR1 + VR2 + VR3
or
VS – VR1 – VR2 – VR3 = 0
R1
I
VS
R3
VR1
VR3+-
VR2
+ - +-
R2
Hukum Kirchoff VoltanDalam sebarang litar elektrik yang
lengkap jumlah algebra bagi d.g.e mestilah bersamaan dengan jumlah algebra kejatuhan (susut) voltan pada perintang dalam litar (gelung) tersebut.
Kirchhoff’s Voltage Law (Example)Kirchhoff’s Voltage Law (Example)
R 1
I
V S
R 3
V R 1 = 4 V
+-
+ - +-
R 2
V R 3 = 6 V
V R 2 = 8 V
Refer to the figure above, calculate the voltage source VS..
Kirchhoff’s Voltage Law (Example)Kirchhoff’s Voltage Law (Example)
Solution
Using Kirchhoff’s Voltage Law
VS – VR1 – VR2 – VR3 = 0
VS = VR1 + VR2 + VR3
= 4 + 8 + 6
= 18 V
Example 1
Find the current value of I1, I2 and I3
R 1= 5Ω R 2=2 Ω
R 4= 4 ΩR 3=3 Ω
I2
I3
I1
E = 12 v
Loop 1 Loop 2
Example 2
Find the current through the resistor 120 Ω,
240 Ω ND 200 Ω by using Kirchoff Law.
E1 = 6V
R1 = 120 Ω
E2 12 V
R2 = 240 Ω
R3
200 Ω
+
-
+
-
Example 3Refer on the below diagram find the value of : -
Currents I1, I2, I3, I4 and I5 using Kirchhoff’sLaw.
1I
20
10V
20
10040
100
I2
I3I1
I4
I5
Thank You