Electrical and Electronics Engineering Lab Date of Conduction:
Experiment: 4
Verification of KCL and KVL
AIM:
[1] To measure voltage and current in a DC circuit for each element
[2] To calculate analytically V & I, compare analytical and practical values
[3] Verify KVL & KCL.
APPARATUS REQUIRED:
Sr. No Equipment Details Rating Type Quantity
1 DC power supply 0-220V 1
2 Voltmeter 0-250V MC 4
3 Ammeter 0-2A MC 3
4 Rheostat 0-400 Ω, 0-370 Ω, Wire wounded Each 01
0-300 Ω, 0-80 Ω
5 Connecting wires 0-2A Multistrands Required
Kirchhoff’s Laws Statement:
Kirchhoff’s Laws are used to solve those networks or circuit where ohms law is may not be readily solved
that circuit. Gustav Kirchhoff’s, a German Scientist, summed up his findings in a set of two laws which
are called Kirchhoff’s Laws. Resistance of a complicated circuits and for calculating the currents flowing
in the various branches of circuits or networks. The two laws are Kirchhoff’s current law and Kirchhoff’s
voltage law.
Kirchhoff’s Current Law (KCL)
This law relates the currents flowing through the circuit that is why this law is called Kirchhoff’s current
law. This law is also known as Kirchhoff’s point law.
This law states that, in any electrical network, the algebraic sum of the currents meeting at a junction or
node is always zero.
Lets us consider a case in which few conductors meeting at a junction or point A, where some conductors
have current entering to the point and some conductors have currents leaving out the point. Assuming
currents entering to the point to be positive while the outgoing currents are negative.
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Electrical and Electronics Engineering Lab Date of Conduction:
We have,
I1-I2-I3+I4+I5=0
I1+I4+I5= I2+I3
Incoming Currents = outgoing Currents
In other words we can say that incoming current is equal to outgoing current.
Kirchhoff’s Voltage Law (KVL)
This law relates the voltages in a closed circuit of an electrical network. It is also known as Kirchhoff’s
mesh law.
Kirchhoff’s voltage law states that the algebraic sum of product of current and resistance in a closed
network is equal to the algebraic sum of EMFs in that closed path that is in a closed circuit.
V1+V2 = IR1+IR2
∑V = ∑IR = 0 or ∑IR = ∑V
In other way we can say that, in a closed circuit or mesh, the algebraic sum of all the EMFs plus the
algebraic sum of products of currents and resistances is zero.
∑V + ∑IR = 0
Procedure:
1. Make connections as shown in circuit diagram,
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Electrical and Electronics Engineering Lab Date of Conduction:
2. Switch ON both power supplies, adjust them to required values.
3. For KVL, Take the readings of voltages Vs,V1,V2, and V3 shown in Voltmeter flowing through
R1, R2 and R3 resistors.
4. Check whether supply voltage is same as sum of the three voltmeter readings.
5. For KCL, Take the readings of the current in Ammeter A1, A2, and A3 flowing through R1, R2
and R3 resistors.
6. Check whether incoming current (A1) is equal to sum of two outgoing currents (A2, and A3)
7. Verify KVL and KCL by comparing analytically calculated values with practical one
Modal Circuit diagram
CIRCUIT DIAGRAM OF KVL:-
V1 MC V2 MC V3 MC
_ _ _
+ + +
+
+ VS
VS
− _ MC
Fig-1
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Electrical and Electronics Engineering Lab Date of Conduction:
CIRCUITDIAGRAM OF KCL:-
+
VS MC
V_
_
Calculation:
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Electrical and Electronics Engineering Lab Date of Conduction:
TABULAR COLUMN
KVL
Vs(V) V1(V) V2(V) V3(V) Total
Voltage
Voltage drops, IR
Drops
Theoretical
Practical
KCL
Vs(V) I1(A) I2(A) I3(A) Total
Current
Current through Node
(I2+I3)
Drops
Theoretical
Practical
Result:
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