Download Lab 0 Instructions and SHEET A

Engr204 Lab 0 – Multiloop Names: ___________________ Lab 0 – A Multiloop Circuit Introduction In this lab activity you will predict (from two circuit models) the currents that you expect in the multiloop circuit shown: 1. You will use the NOMINAL values for the resistances and voltages, i.e. if the color bands on your resistor give you 100 Ohm, you will use 100 Ohm in your calculations. If your battery is a '9V' battery, use 9V. 2. You will use the REAL values for the resistances and voltages, i.e.you will use your multimeter to measure the resistance of each resistor and the voltage of each battery, and use this information in your calculations. You will then MEASURE all currents i1 to i6 and compare your predicted (calculated) and measured values. Instructions 1. For the circuit shown, calculate currents i1 to i6, using nominal values for resistances and voltages. Express your answers in mA, round to the nearest tenth of a milliamp. Put your answers in table 2. 2. ACTUAL values for R1 to R6: Use your multimeter to measure the values for R1 to R6 (make sure resistors are disconnected from circuit when you take the measurement). Put your data in table 3. 3. Set up your circuit, using the equipment from your circuits kit. Try to make the actual circuit look similar to the circuit diagram (this will help to troubleshoot the circuit). 4. Measure vs1 to vs3 while the batteries are connected to the circuit. Put your data in table 3. 5. Measure all currents (i1 to i6) and put your results into tables 2 and 4. Remember that you have to break the circuit to do this. Watch polarity! 6. Re‐measure your three voltages. If they have changed, use the new value instead of the earlier one. 7. Calculate currents i1 to i6, using real values from table 3. Express your answers in mA, round to the nearest tenth of a milliamp. Put your results in table 4. 8. Calculate errors. Use the measured value as the true value. 9. Instructions for submission: Submit a hardcopy of the work showing your circuit analysis (i.e. KVL, KCL etc.), only for nominal values (SHEET A). Download an electronic copy of the Excel data sheet (SHEET B) from the course website, fill out, and submit BOTH as hardcopy and as an email attachment (filename: Engr204_Lab0_yourlastnames). Engr204 Lab 0 – Multiloop Names: ___________________ Sheet A: Use KVL and KCL to find currents i1 to i6. Use the given nodes, reference polarities and reference currents. Given: vs1=9V vs2 = 9V vs3 = 1.5V R1 = 43 R2 = 1k R3 = 300 R4 = 51 R5 = 100 R6 = 1.5k a. Set up the equations. Be clear and clean and list them ‘Excel‐ready’. b. Use Excel, or some other tool to find the currents. Note: if I don’t understand your work right away, there may be a deduction. Lab 0
Lab 0: A Multiloop Circuit
Names: Data and Analysis ‐ SHEET B
Table 1: NOMINAL values for R1 to R6 and vs1 to vs3
Table 2: NOMINAL: Compare calculated and measured currents i1 to i6
calculated measured relative error Current
(mA)
(mA)
(%)
vs1
9V
vs2
9V
i1
vs3
1.5 V
i2
R1
43 Ohm
i3
R2
1000 Ohm
i4
R3
300 Ohm
i5
R4
R5
R6
51 Ohm
100 Ohm
1500 Ohm
i6
Table 3: REAL values for R1 to R6 and vs1 to vs3
Table 2: NOMINAL: Compare calculated and measured currents i1 to i6
Fill in the measured values for R1 to R6 and vs1 to vs3
Current
vs1
V
vs2
V
i1
vs3
V
i2
R1
Ohm
i3
R2
Ohm
i4
R3
Ohm
i5
R4
Ohm
i6
R5
Ohm
R6
Ohm
calculated (mA)
measured
(mA)
relative error (%)
Briefly discuss your findings:
Note: When you design a product as an electrical engineer, the functionality of your device should not be sensitive to the difference between nominal and real values. We only explored this in this activity to see how well we can predict our circuit's behavior.