Kirchoff's Voltage and Current Laws

ENGINEERING lAB 13:191 Men who celebrate the praises of Allah, standing, sitting, and lying down on their sides, and contemplate the(wonders of) creation in the heavens and the earth, (With the thought): "Our Lord! not for naught Hast Thoucreated (all) this! Glory to Thee! Give us salvation from the penalty of the Fire.Electric Circuits Lab Experiment 2Kirchoff’s Voltage and Current LawsAim:• To verify Kirchhoff’s voltage and current laws.Apparatus:• One d.c. supply 10V• Three digital multimeters• Resistors 300Ω (2), 330Ω, 1.8kΩ, 2.7kΩ, 3.0kΩ• PSpice softwareCircuit diagrams :Mesh 3ABEMesh 1 Mesh 2CDFigure 2-114

ENGINEERING lAB 1Method:(a) Kirchhoff’s Voltage Law :1. Measure the resistance of each resistor. Set the supply voltage to 10V. Record themeasured values in Table 2-1a.2. Construct the circuit shown in Figure 2-13. Commence at point A and measure the potential difference between each successivepair of lettered terminals for Mesh 1. i.e A-B, B-C , C-D and D-A. (Note :DMM’s probeshave to placed consistently.)4. Record down the measured values in Table 2-1b.5. Measure the potential difference for the points AC, CE and EA. Verify kirchoff’s voltagelaw using the displayed values. (Note that V CA is actually V C – V A ). What can be deducedfrom this condition? Record the measured values in Table 2-1c.(b) Kirchhoff’s Current Law:6. Measure the branch currents entering node A by placing ammeter as shown in Figure 2-1.7. Record the magnitude and the direction of the current as indicated by each ammeter inTable 2-2.Analysis, deductions and conclusion:1. Has Kirchhoff’s laws been verified? What facts determined for the results of this testsupport this decision?2. Do the test results compare favorably with those simulated by PSpice? What could besome of the causes for the discrepancies?3. Are there any circuit configurations for which Kirchhoff’s laws are not applicable?Substantiate your answer.4. For what type of circuit configurations would it be prudent not to apply Kirchhoff’s laws?Pspice Analysis 11. Utilising measured values of resistors and supplies, construct a schematic diagram forFigure 2.1. Display the voltages and current values using P-Spice. Verify Kirchoff’svoltage law. Record your results and find the relative error.2. Tips:By inserting the current probes as in the schematic, desired results can be obtained fromthe output.From the schematic window, you can obtain PSpice outputAnalysis tab –> Examine Output. Study the output.Note the sign for the branch currents.Double clicking the IPROBE to acquire the part’s name by enabling both boxes.Sample of output is as followsVOLTAGE SOURCE CURRENTS15

ENGINEERING lAB 1NAMEV_V1v_V2v_V3v_V4CURRENT-2.950E-03-2.238E-034.323E-041.806E-033. Record the magnitude and the direction (-ve-into node , +ve-out of node) of the currentsat each ammeter position. Using the values of the branch currents from the output, verifyKirchoff’s current law. Assign proper title to the schematic and thus output for submissionMarking SchemeInformation for each formatted categories must be provided as outlined in the introduction.II.III.III.IV.Valid plot (area enclosed must be bounded andsymmetrical so as to cancel +ve & -ve areas) - 2 pts.Tabulated results - 2 pts.PSpice schematic with displayed results, and output - 4pts.Discussion and conclusion by attempting all questions - 2 pts.16

ENGINEERING lAB 1Table of ResultsMeasured components valuesV1 R1 R2 R3 R4 R5 R6Table 2-1aReferencepointsA-BB-CC-DD-APotentialDifference(V)Measured ValuesSign (+ or -)Table 2-1bTheoretical ValuesPotentialDifference(V)Sign (+ or -)ReferencepointsA-CC-EE-APotentialDifference(V)Measured ValuesSign (+ or -)Table 2-1cTheoretical ValuesPotentialDifference(V)Sign (+ or -)Resistance Current Current directionR3R4R6Table 2-214