LABORATORY MODULE
Fundamental of Electrical Engineering
(ENT 163/4)
Semester 1 (2008/2009)
Experiment 2:
Kirchhoff’s Law
Name
:_________________________________________
Matric No. :________________
Name
:_________________________________________
Matric No. :________________
Name
:_________________________________________
Matric No. :________________
School of Mechatronic Engineering
Universiti Malaysia Perlis (UniMAP)
EXPERIMENT 2
KIRCHHOFF’S LAW
1. OBJECTIVE:
1.1 Verify Kirchhoff’s current and voltage law.
1.2 Improve understanding on circuit analysis method.
2. INTRODUCTION:
From our consideration of series and parallel connections of resistor, we have observed
certain condition appertaining to each form of connection. For instance, in series circuit,
the sum of the voltage across each component is equal to the applied voltage, and for
parallel networks, the sum of the currents in the branches equal to the supply current.
Thus, that condition may state as below:
Kirchhoff’s current law. At any algebraic sum of the currents at the junction in the
network zero. Different signs are allocated to currents held to the flow towards the
junction and those away from it. For flow toward the sign is positive and negative for
current away from the branches.
Figure 2.1: Illustration Of Kirchhoff’s Current Law
From the figure 2.1 above the equation below describe the relationship between I1 , I2 ,
I3 I4 and I5 .
I1+I3=I2+I4=I5
(1)
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Kirchhoff’s voltage law. At any instant in a closed loop, the algebraic sum of the emf ‘s
acting round the loop is equal to the algebraic sum of the pds round the loop.
Figure 2.2: Illustration of Kirchhoff’s Voltage law.
As in figure 2.2, using Kirchhoff’s law voltage counter clockwise we ca write the the
equation as follow:
V1+V4=V2+V3
(2)
3. COMPONENTS AND EQUIPMENTS:
3.1 Breadboard – 1 unit
3.2 DC power supply – 1 unit
3.3 Digital Multimeter – 1 unit
3.4 Wires
3.5 Resistors:
3.5.1 1 kΩ resistor - 2 pcs
3.5.2 2.2 kΩ resistor - 2 pcs
3.5.3 4.7 kΩ resistor - 1 pcs
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4. PROCEDURE:
4.1 Kirchhoff’s Current Law.
4.1.1 Consider the circuit in Figure 2.3. Calculate theoretically current IT when
V = 5V. Record the value and verify the theoretically Kirchhoff’s Current Law
between node A and node B in pre-lab calculation.
Figure 2.3 : Experiment Setup
4.1.2 Connect the circuit shown above Figure 2.3 on the breadboard
4.1.3 Turn on DC power supply at 5V. By using the multimeter, measure the
current that flow through every resistor and record the value.
4.1.4 Prove Kirchhoff’s Current Law practically.
4.1.5 Repeat step 3 and 4 by increasing the power supply to 10V.
4.1.6 Record the value in Table 2.1.
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4.2 Kirchhoff’s Voltage Law.
4.2.1 By referring the same circuit Figure 2.3. Calculate theoretically voltage across
every resistor when V = 5V. Record the calculation and verify theoretically
Kirchhoff’s Voltage Law for all closed loop below:
i. V,R5,R1,R4
ii. V,R5,R2,R4
iii. V,R5,R3,R4
4.2.2 Turn on DC power supply at 5V. By using multimeter, measure voltage drop
across every resistor. Record all measurement.
4.2.3 Prove Kirchhoff’s Voltage Law practically.
4.2.4 Repeat step 2 for V=10V.
4.2.5 Record the value Table 2.2.
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Name
:
______________________________
Matrix No
:
______________________________
Date : ______________
5. RESULT:
PRE LAB CALCULATIONS.
V = 5 V.
5.1 Kirchhoff’s Current Law at node A.
5.2 Kirchhoff’s Current Law at node B.
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Name
:
______________________________
Matrix No
:
______________________________
Date : ______________
5.3 Kirchhoff’s Voltage Law for loop V,R5,R1,R4.
5.4 Kirchhoff’s Voltage Law for loop V,R5,R2,R4.
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Name
:
______________________________
Matrix No
:
______________________________
Date : ______________
5.5 Kirchhoff’s Voltage Law for loop V,R5,R3,R4.
Table 2.1
DC Voltage Power Supply (V)
Current
V=5V
V=10V
ITotal(mA)
IR1(mA)
IR2(mA)
IR3(mA)
IR4(mA)
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Name
:
______________________________
Matrix No
:
______________________________
Date : ______________
Table 2.2
DC Voltage Power Supply (V)
Voltage
Drop
V=5V
Calculation
Experiment
V=10V
VR1(V)
VR2(V)
VR3(V)
VR4(V)
VR5(V)
6. EXERCISE:
6.1 Write down current relationship for junction a, b and c of the network shown in
figure below and determines the currents I3, I4 and I5.
Junction a;____________________________________________________
Junction b;____________________________________________________
Junction c;____________________________________________________
I3=_________A
I4=_________A
I5=_________ A
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Name
:
______________________________
Matrix No
:
______________________________
Date : ______________
7. DISCUSSION:
8. CONCLUSION:
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