1. The document describes an electrical circuits lab experiment on verifying Kirchoff's current and voltage laws. It provides objectives, equipment used, theoretical background, sample calculations, circuit diagrams, and conclusions. 2. Key aspects covered include stating Kirchoff's laws, applying the laws to determine currents and voltages in series and parallel circuits with one source, and using mesh equations to solve circuits with two sources. 3. Through this experiment, students learn to apply Kirchoff's current and voltage laws to analyze circuit behavior, determine currents and voltages, and solve circuits with multiple sources. Sample calculations verify the theoretical predictions.

1. 1
Palestine Polytechnic University
Collage of IT and Computer Engineering
Computer Systems Engineering Department
Electrical Circuits Lab
Experiment Title: Kichhoff's Laws
Experiment Number: 5
Date: 11 March 2013
Instructor:
Zahir Sa'afeen

2. 2
Objectives:
 To verify Kirchoff voltage and current law.
 To be able to apply Kirchoff current and voltage law with two
sources.
Equipments:
1. FACET base unit.
2. DC fundamental circuit board.
3. Digital Multimetre.
4. Wires.
5. Software(Multisim).
6. Ammeter.
Theory:
Kirchoff's current law states that :
At any node (junction) in an electrical circuit, the sum of currents flowing
into that node is equal to the sum of currents flowing out of that node, or:
The algebraic sum of currents in a network of conductors meeting at a
point is zero.
 KCL applies to all parallel circuits.
 R=E/I for every branch.
 It = I1+I2+I3+.....+In
Kirchoff's voltage law states that:
The directed sum of the electrical potential differences (voltage)
around any closed network is zero,
Mesh Current Equation for closed path in circuit
For loop(1): I1R1+I1R3-I2R3 =Vs1
I1R1+(I1-I2)R3 =Vs1

3. 3
For loop(2): I2R2+(I1-I2)R3 =Vs2
Calculations and Analysis:
Kirchoff's current law
Exercise 1:
R1 = 1800 ± 5% Ω (using color code)
R2 = 2200± 5% Ω (using color code)
IR1 =VR1/R1=
14.98
1800
= 8.31 mA
IR2 =VR2/R2=
14.98
2200
= 6.79 mA
IT = IR1 + IR2 =8.31+6.79 = 15.10 mA.
Exercise 2:
IR1 =Vs/R1=
14.98
1800
= 8.31 mA
IR2 =Vs/R2=
14.98
2200
= 6.79 mA
IT = IR1 + IR2 =8.31+6.79 = 15.10 mA.
IT = Vs(R1+ R2)/(R1* R2)=
14.98∗4000
1800∗2200
= 15.13 mA.
Kirchoff's voltage law
Exercise 1:
R1 = 220 ± 5% Ω (using color code)
R2 = 510± 5% Ω (using color code)
R3 = 750± 5% Ω (using color code)
Rt = R1+R2+R3 =220+510+750= 1480 Ω
IT = Vs/Rt =
14.98
1480
= 10.12 mA
VR1 = It * R1 =10.12*220=2.22 V
VR2 = It * R2 =10.12*510=5.16 V
VR3 = It * R3 =10.12*750=7.59 V

4. 4
Vt = VR1+VR2+VR3 = 2.22+5.16+7.59=14.97V.
Kirchoff's Solution with 2 Sources
Exercise 1:
R1 = 750 ± 5% Ω (using color code)
R2 = 3600± 5% Ω (using color code)
R3 = 7500± 5% Ω (using color code)
Rt = R1+R2+R3 =220+510+750= 1480 Ω
IT = Vs/Rt =
14.98
1480
= 10.12 mA
VR1 = It * R1 =10.12*220=2.22 V
VR2 = It * R2 =10.12*510=5.16 V
VR3 = It * R3 =10.12*750=7.59 V
Vt = VR1+VR2+VR3 = 2.22+5.16+7.59=14.97V.
VS1 - VR3- VR1= 10-5.97-3.61=.42 V
VR2 - VR3- VS2= 1.15 V
Exercise 2:
IR3 = VR3/R3 =
6.62
7500
= .88 mA
IR1 = (VS1-VR3)/R1=
10−6.62
750
= 4.54 mA.
VR1 = IR1 * R1 =4.5*750=3.38 V
IR2 = (VS2+VR3)/R2=
10+6.62
3600
= 4.6 mA.
VR2 = IR2 * R2 =4.6*3600=16.56 V
IR1 = IR2 + IR3 =4.6+.88 = 5.48 mA.

5. 5
Experimental circuits and exercises:
Exercise 5 :
Kirchoff's Current Law
Kirchoff's Voltage Law

6. 6
Kirchoff's Solution with 2 sources

7. 7
Conclusions:
After this experiment we are able to determine current in parallel
branches by using Kirchoff's current law and verify it by measure and
calculations . Also, we are able to determine voltage of series resistance
and to use KVL and verify it by measure and calculation. Moreover, we
can deal with circuits with two sources by applying mesh equation
,KVL and KCL.