Verification of Superposition Theorem

Experiment No.: 5

Experiment Name:

Use voltmeter, ammeter to determine current through the given branch and voltage across the given element of circuit by applying Superposition Theorem.

Objective:

To verify Superposition theorem.

Theory: This theorem may be stated as follows, “In a network resistance containing more than one generator (or source of emf) the current which flows at any point is the sum of all the currents which would flow at the point if each generator where considered seperately and all the other generators replaced for the time being by resistors equal to their internal resistance.”

Circuit Diagram:

Observation Table: R₁ = 112 Ω, R₂ = 53 Ω, R₃ = 100 Ω

Sl. No.	Voltage Source	I1 (mA)	I2 (mA)	I3 (mA)
1.	V1 = 20 V acting alone	130	90	47
2.	V2 = 10 V acting alone	20	50	73
3.	V1 and V2 both are acting	115	140	25

Calculation:

When 20 V source is acting alone:

When 10 V source is acting alone:

When 10 V & 20 V sources both are acting:

According to Superposition Theorem,

I₁ = I₁‘- I₁” = 112.76 mA

I₂ = I₂‘+ I₂” = 139.06 mA

I₃ = I₃‘- I₃” = 26.29 mA

Apparatus Used:

Sl. No.	Name of the Apparatus	Specification	Quantity	Maker’s Name
1.	Network theorem trainer kit		1	M.E.W.
2.	Milli-ammeter	PMMC, 0-150 mA	3
3.	Resistor	112 Ω, 53 Ω, 100 Ω	3

Remarks:

The observed values and calculated values are nearly same. The difference between the is for instrumental and observational error. Neglecting this error Superposition Theorem is verified successfully.