Introduction
Introduction
The Kirchhoff's Law.
It is good for students to know the algebraic sum of the currents at any junction or node and the emf's and the resistance voltage drops in any closed loop of an electric circuit is zero.
The students will determine the current in a DC network using Kirchhoff’s laws and compare the results with the calculated values in the circuit.
Task
Task
Students will be split up into 20 pairs. They will follow the given procedures and get the desired measured values and compare it to the calculated values by using Ohm's Law and Kirchhoff's Law.
Students will be graded out of a possible 16 points from the rubric in this lesson.
This activity will be in 3 hours or 1 session duration.
Process
Procedure
The activity will need the following materials:
1 – Circuit Trainer
1 – Power Supply
10 – Connecting Leads
2 – Multi Testers
Reminder: Write your data in a A4 size of coupon bond.
Step 1: Draw the required circuit for this activity then present your drawing to your instructor before you proceed to step 2. Make sure you include these elements (Switch 1 and 2, R1, R2, R3, Source Voltage 1 and Source Voltage 2).
Step 2: Set-up the materials as shown in your drawn circuit, leaving switch open.
Step 3: With the switches closed, measure the voltages V1 and V2 across the batteries with a voltmeter. Record these values. After you have measured the voltages, open the switches.
Step 4: Considering that the values of R1, R2, R3, V1, and V2 are already known, compute for the currents I1, I2, and I3 passing through R1, R2, and R3 respectively by using Kirchhoff’s Laws. Indicate the direction of the currents through each resistor.
Step 5: Show your solution in finding the values of your current.
Step 6: Break the connection at R1 and insert the ammeter in series with this resistor. Close the switch. Read the meter and record the value of current I1. Do the same with R2 and R3 to get the currents I2 and I3.
Step 7: Determine the percentage error between the computed and measured values.
Step 8: Show your solution in finding the Percentage of Error.
Don't forget to provide your discussion or observation with your pair.
LET'S START NOW AND HAVE FUN!
Evaluation
Evaluation
This is how your work be evaluated.
| Performance Indicator (PI) | Beginning (1) | Developing (2) | Meets Expectations (3) | Exceeds Expectations (4) |
| Functionality | No output generated |
Output generated but did not fully meet the problem statement and conditions.
|
Output generated based on the problem statement and conditions. Implements the design with a little accuracy. |
Output generated based on the problem statement and conditions. Implements the design with utmost accuracy. |
| Perform Experiment |
Unable to operate instrument and equipment.
|
Need some guidance in instrumentation and equipment operation.
|
Able to operate almost of the instruments and equipment with supervision
|
Able to operate instrument and equipment with minimal supervision. |
| Use of equipment |
Do not follow good and safe laboratory procedures.
|
Follow some good and safe laboratory procedures.
|
Follow good and safe laboratory procedure most of the time.
|
Follow good and safe laboratory procedures at all times. |
|
Correlation between data and theory |
Cannot identify variable to measure. No conclusions at all and no relationship between data and the theory.
|
Have some trouble identifying variables to measure and/or to calculate. Conclusions are poor with a little relationship to the theory.
|
Clearly identify almost all of the variable to measure and to calculate. Conclusions are correct but data does not correlate with the theory.
|
Clearly identifies variables to measure and calculates correctly. Conclusions are exact and relating data to theory.
|
Conclusion
Conclusion
Now I want you to think about what you learned and see if you understand the information. Compare the circuit parameters measured in the previous steps with the values you calculated in the given steps. Are the values close to each other or not and why, and why not?
Credits
Author Biography
Engr. Paul John P. Infante, REE, RME
I am a faculty of College of Engineering Education under Electrical Engineering Cluster teaching Physical Sciences and Professional courses.