OBJECTIVE: VERIFICATION OF KIRCHHOFF’S LAWS
i) Kirchhoff’s current law(KCL) ii) Kirchhoff’s voltage law(KVL)
APPARTAUS REQUIRED:
Sl no.
Apparatus
Type
Range /specification
Qty.
1
Experimental board
Kit or
Bread Board
1
2 Power supply
DC
9V & 5V
1
3
VOLTMETER
Moving-Iron
0-15V
1
4
AMMETER
Moving-Iron
0-100mA
1
5
CONNECTING WIRES
As required
THEORY:
I) Kirchhoff’s current law (KCL): It states that the total algebraic sum of current meeting at the junction is zero. This law is based on the principle of conservation of charges.
KCL at junction “O”
I1+ I2+ I3+ I4 - I5 - I6 =0
Therefore, I1+ I2+ I3+ I4 = I5+I6
CIRCUIT DIAGRAM:
PROCEDURE:
i) Connect the circuit. As shown in circuit diagram. ii) Switch on the power supply. iii) Note the reading of ammeter
OBSERVATION TABLE:
Sl no.
I1 (A) practically I2 (A) practically I3 (A) practically I3 (A) calculated I3 = I2+I1
CALCULATION OF CURRENT “I3”
I3 = I2+I1
RESULT:
Add the reading of ammeter 1(A1) & ammeter 2(A2) and it will be equal to reading of ammeter 3(A3)
I3 = I2+I1
KCL is verified.
PRECAUTION:
i) All connection should be tight. ii) Before connecting the instruments check their zero reading. iii) The terminal of the resistance should be properly connected.
ii) Kirchhoff’s voltage law (KVL):
It states that the algebraic sum of voltage through a closed loop is zero. This law is based on the principle of conservation of energy,
Where, is the branch voltage of close path.
CIRCUIT DIAGRAM:
PROCEDURE: iv) Connect the circuit. As shown in circuit diagram.
v) Switch on the power supply vi) Note the reading of voltmeter. V1,V2,V3 (with polarity)
.
OBSERVATION TABLE:
Sr No
Supply voltage
V1
V2
V3
(Mesh 1)
(Mesh 2)
1
9V
2
5V
3
9V & 5V
RESULT:
The algebraic sum of