University Lab Report: Superposition Theorem in Electrical Circuits

This lab report investigates the superposition theorem in electrical circuits. The experiment involved constructing a T electrical network and measuring voltages and currents under different conditions. The report details the procedure, including measurements with and without voltage sources. Calculations were performed to determine theoretical values, which were then compared with the experimental results. The study aims to verify the superposition theorem both theoretically and practically, accounting for potential discrepancies due to the digital multimeter's internal resistance. The report includes tables of measured and calculated values, providing a comprehensive analysis of the circuit behavior. The objectives of the lab were successfully achieved by demonstrating the validity of the superposition theorem.

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Lab Report 3: Superposition Theorem in Electric Circuits
Aims and objectives
1. To investigate the superposition theorem applied to electrical circuits
2. To calculate voltages and currents at different points of a circuit
3. To compare the calculated and measured values
Apparatus used
1. Power supply
2. Bread board
3. Digital multimeter
4. Resistors
5. Connecting wires
Procedure
Before beginning the experiment, the values of voltages across resistors and currents through
them were calculated for supply voltages of 10 and -15 V.
A T electrical network was then constructed on the bread board and the voltage source
connected. The voltages across the resistors (V1 to V5) were measured and recorded. The
voltages Vab, Vbc, Vcd, Va, Vb, Vc and Vd were also measured and recorded. To calculate
the voltages at different points in the circuit, the voltage sources were disconnected in turns
such that only one source was feeding the circuit at a time.

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With the -15 V supply disconnected, the circuit parameters were measured (the 10 V supply
was replaced with a short circuit). The procedure was then repeated with -15 V now removed
and replaced with a short circuit.
Circuit diagrams
Results and discussion
Before beginning the experiment, the different currents, voltages and resistances were
calculated. The calculations were performed for both -15 and 10 V voltages. The results were
then recorded in the table below.
Experiment 02
With the -15 voltage source replaced with a short circuit, the effects of the 10 V power supply
were noted. The total resistance Rt was measured. The voltages across and the currents
through the resistances at the specified points in the procedure were also measured (V1 to
V5). The voltage, current and resistance are in V, mA and ohms respectively.

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Experiment 03
With the 10 V power supply short circuited, the effect of the -15 V supply on the circuit was
noted. The procedure was repeated as for experiment 2 above. The measured values are
presented in the tables below,
Finally, a comparison between the measured and calculated values was performed for both
the 10 V and -15 V power supplies. The results are recorded below.

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Conclusion
From the results presented above, we were able to verify the superposition theorem both
theoretically and practically as. A small difference was observed between calculated and
measured values. This can be attributed to the internal resistance of the digital multimeter.
The set objectives were therefore achieved.