Topics: Kirchhoff's circuit laws, Volt, Electrical measurements Pages: 4 (332 words) Published: October 28, 2013
﻿EXPERIMENT NO: 1
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

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...