Series and Parallel Resistors Lab

  https://phet.colorado.edu/en/simulation/circuit-construction-kit-dc-virtual-lab Here, you will be able to build circuits by dragging and dropping components from their locations on either side of the screen. Note that you can scroll up and down on the left hand 'component carousel'. You can change the values of components by clicking on them and adjusting the resulting sliders. You can also change the orientations of components (and, for wires, their lengths) by clicking and dragging on one end of the component. For Part I of the lab, your job is to build a circuit with 3 resistors in a series circuit with a battery. Insert an ammeter (also in series) to measure the current. Make sure that you choose battery and resistor values that give you at least 3 significant figures in your measurements. If your ammeter reads 0.001 A, then you only have one significant figure. Don't do that. Calculate the equivalent resistance on Desmos. To Use Desmos: Navigate to the link here. (Links to an external site.) (or: https://www.desmos.com/calculator (Links to an external site.)), We are not plotting anything, so just work on the left hand side of the screen. You can create variables by typing into the 'cells' on the left side of the screen. You make a subscript by typing the 'underline' character: (Shift + -) . To escape from the subscript, just use the 'up' arrow key (or click to the right of the subscript). You will put in the values for R1, R2 and R3 in the cells. In the next cell input Res = R1 + R2 + R3. The result should appear in the same cell. You will use a similar procedure with Desmos when you calculate values for the resistance in Part II of the lab. Now that you have your equivalent resistance, go back to the Phet and build the circuit with the equivalent resistance. Put an ammeter in series with the resistor and the battery. Compare the currents in both circuits. If the circuits are equivalent, then you should obtain the same (or nearly the same) current in both circuits. If the disagreement is in the last significant figure, then your results agree within a 1% error, or less (it could be as low as about 0.1%). Next bring up the Phet with the circuits and the Desmos view at the same time. You can pull one of the browser tabs out of the browser to make it appear in its own browser. Show your lab and the Desmos calculations side by side. Since we don't care about the graph, you can just drag over the Desmos browser, so that the lab hangs off of the right side of the screen. This will free up more room so you can maximize the size of the Phet's browser. Make sure to check the Labels and Values checkboxes in the upper right side of the page. This guarantees that your screenshots will include labels for your components and all of the data that would otherwise have to go into your data table. Take a screen shot of the side by side browsers. The result should be something like this: DC Circuit Lab and Desmos.png Note that I used 1000 V batteries to insure 3 digit accuracy in my current readings. I also had to change from the banded type resistor (which has a maximum value of 120 ohms) to the olive colored resistor (which can take on values of 100 ohms to 10,000 ohms). You may have to do something similar (you can also change the resistor values to get 3 digits of accuracy in the ammeter). Repeat the above procedure two more times, with different resistor values by clicking on all of the resistors and adjusting their values. You may vary the battery's voltage as well, but that is not required. By demonstrating that we get the same current values, we are confirming that the equivalent resistance is indeed equivalent to the three separate resistances attached in series. For Part II of the lab, we now do 3 data runs with different combinations of 3 parallel resistors. You are to again compute the equivalent resistance with Desmos (Use the formaula: Rep=11R1+1R2+1R3 .) and build the circuit with the equivalent resistance. Check the Labels and Values checkboxes as before. Do a screenshot of the side by side Phet and Desmos windows. Repeat with different resistor values until you have a total of 3 parallel circuit data runs. An example of one data run is shown below. DC Circuit Lab and Desmos Parallel.png Lab Report: This will be much easier for today's lab, because we already have the Apparatus (with labels), Raw Data, and 3/25/2021 Order 340197832 https://admin.writerbay.com/orders_available?subcom=detailed&id=340197832 3/4 even the Calculations all in your six screenshots (3 for series resistors and 3 for parallel resistors). Your percent error should be so small, that there is no need to calculate the percent error in this lab. (If it is greater than 1%, then you probably did something wrong. Go back and fix it.) State a title for your lab report, Series and Parallel Resistors, is probably best. We will be using the DC Circuits Lab again, so don't use that for your title. Introduction: Ex. We are using a dc circuits lab to model series and parallels resistors. We use these models to test the parallel and series equivalent resistance formulas. Use your own words here. Apparatus: Place all of your screenshots here. There should be no need to label it (assuming that you checked the Labels and Values checkboxes each time). Procedure: This can also be short today: Follow the procedure below for Series resistances (Part I) and Parallel resistances (Part II). 1. Go the the DC Circuit Lab website. 2. Build the circuits shown. 3. Show Desmos calculations for equivalent resistance values. 4. Change the resistor values and repeat. Normally, I don't want you to discuss calculations in the Procedure section, but, in this case, since you are including the Desmos calculations in your screenshot, you should put it in the instructions. Raw Data: Refer the user to the screenshots in the Apparatus section above. Calculations: Refer the user to the screenshots in the Apparatus section above. Conclusions: Point out that the measured currents in the equivalent currents were the same (or agreed to less than 1%), thus confirming the formulas in this case. Unless that is not what happened, in which case you need to review your work in this lab.