KCL & Current Divider Rule
Lab#07
LAB#07
OBJECTIVE
Verification of KCL & Current Divider Rule.
EQUIPMENT REQUIRED
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Multi Meter
DC Power Supply
Different Valued Resistors
Bread Board
THEORY
KCL
KCL states that the sum of the currents entering any node equals the sum of the
currents leaving the node.
ΣIentering = ΣIleaving
Current Divider Rule
The Current Divider Rule is given by
Ix = (Rp/Rx) I
Where,
Rp is the equivalent resistance of a parallel circuit
CIRCUIT DIAGRAM
V1
5Vdc
R1
R2
R3
1k
2k
3k
Figure 7.1
Basic Electrical Circuits & Machines
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KCL & Current Divider Rule
Lab#07
PROCEDURE
 Connect two resistors R1 and R2 in parallel to a DC power supply as shown in
Figure 7.1. Set E = 10V from the trainer board.
 Take readings of I1, I2 and I using ammeters
 Verify KCL (i.e. I = I1 + I2).
 Find Rp using the equation
 Verify Current Divider Rule (i.e. I1 = (Rp/R1) I & I2 = (Rp/R2) I
OBSERVATION
TABLE 7.1
Nominal Value
Measured Resistance
R1 =
R2 =
R3 =
MEASURED VALUES
Current across R1 = _____________
Current across R2 = _____________
Current across R3 = _____________
Total Current = _________________
CALCULATED VALUES
Current across R1 = _____________
Current across R2 = _____________
Current across R3 = _____________
Total Current = _________________
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KCL & Current Divider Rule
Lab#07
EXERCISE
Q1) Determine the voltages registered by a voltmeter between the following points in this
circuit:
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VA = __________ (Red lead on A, Black lead on ground)
VB = __________(Red lead on B, Black lead on ground)
VC = __________(Red lead on C, Black lead on ground)
VD = __________(Red lead on D, Black lead on ground)
Q2)
Determine what a digital voltmeter would indicate if connected between the following points:
 Red lead on A and Black lead on ground = ______________
 Red lead on B and Black lead on ground = ______________
 Red lead on A and Black lead on B
= ______________
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KCL & Current Divider Rule

Red lead on B and Black lead on A
Lab#07
= ______________
Q3) What will happen to the current through R1 and R2 if resistor R3 destroy?
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Q4) We know that the voltage in a parallel circuit may be calculated with this formula:
E = ITRT
We also know that the current through any single resistor in a parallel circuit may be
calculated with this formula:
Combine these two formulae into one, in such a way that the E variable is eliminated,
leaving only Ir expressed in terms of IT, RT, and R.
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