LABORATORY MODULE
ENT 163
Fundamental of Electrical Engineering
Semester 1 (2006/2007)
EXPERIMENT 2 : Kirchhoff’s Law
Name
:____________________________________________________
Matrix No.
:______________________
School of Mechatronic Engineering
Northern Malaysia University College of Engineering
ENT 163 - Fundamental of Electrical Engineering
Laboratory Module
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. PARTS AND EQUIPMENT:
2.1
Breadboard – 1 unit
2.2
DC power supply – 1 unit
2.3
Digital Multimeter – 1 unit
2.4
Wires
2.5
Resistor :
2.5.1
1 kΩ resistor - 2 pcs
2.5.2
2.2 kΩ resistor - 2 pcs
2.5.3
4.7 kΩ resistor - 1 piece
3. 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.
Page 1 of 8
ENT 163 - Fundamental of Electrical Engineering
Laboratory Module
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)
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
equation as follow:
V1+V4=V2+V3
Page 2 of 8
(2)
ENT 163 - Fundamental of Electrical Engineering
Laboratory Module
4. PROCEDURE:
4.1 PART (A) : Kirchhoff’s current law.
4.1.1
Consider the circuit in figure 2.3. Calculate theoretically current IT when
V = 5 V. 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 law practically.
4.1.5
Repeat step 4.1.3 and 4.1.4 by increasing the power supply to 10V and
15V
4.1.6
Record the value in Table 2.1.
Page 3 of 8
ENT 163 - Fundamental of Electrical Engineering
Laboratory Module
4.2 PART (B) : 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,R1,R2,R5
ii. V,R1,R3,R5
iii. V,R1,R4,R5
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 law practically.
4.2.4
Repeat step 4.2.2 for V=10V and V=15V
4.2.5
Record the value Table 2.2.
Page 4 of 8
ENT 163 - Fundamental of Electrical Engineering
Laboratory Module
Name :
______________________________
Matrix No :
______________________________
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.
Page 5 of 8
Date : ______________
ENT 163 - Fundamental of Electrical Engineering
Laboratory Module
Name :
______________________________
Matrix No :
______________________________
Date : ______________
Table 2.1
DC Voltage Power Supply (V)
Current
V=5V
V=10V
V=15V
ITotal(mA)
IR1(mA)
IR2(mA)
IR3(mA)
IR4(mA)
Table 2.2
DC Voltage Power Supply (V)
Voltage
Drop
V=5V
Calculation
Experiment
VR1(V)
VR2(V)
VR3(V)
VR4(V)
VR5(V)
Page 6 of 8
V=10V
V=15V
ENT 163 - Fundamental of Electrical Engineering
Laboratory Module
Name :
______________________________
Matrix No :
______________________________
Date : ______________
6. EXERCISE:
6.1
From figure below, what is value of VJ?
Determine the value of IJ if I1 = 0.47 A and I2 = 0.12 A.
VJ = ________V
6.2
IJ = ________A
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
Page 7 of 8
I5=_________ A
ENT 163 - Fundamental of Electrical Engineering
Laboratory Module
Name :
______________________________
Matrix No :
______________________________
Date : ______________
7. DISCUSSION:
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
8. CONCLUSION:
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
Page 8 of 8