College Physics PhET Resistivity Simulations EPCC Goal : Learn about resistivity. Check the link in figure 1. Learn more about how a resistor resists current based on its physical characteristics....

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College Physics PhET Resistivity Simulations EPCC Goal : Learn about resistivity. Check the link in figure 1. Learn more about how a resistor resists current based on its physical characteristics. Change the following parameters of the resistor according to the settings below. Remember to reset the simulation for every case: 1. Vary the length of the resistor, keeping all things constant 2. Vary the cross-sectional area, keeping all other things constant 3. Vary the resistivity, keeping all other things constant Problems: 1. Make notes on what you learned from this simulation. Write a synopsis (no more than 5 sentences) on what you learned from the simulation. 2. Calculate the maximum and minimum conductivity based on the maximum and minimum resistance you got from this simulation. What type of relationship does the resistivity has with conductivity of a material? Figure 1: PhET simulation on resistivity. Use this link to access the simulation: https://phet.colorado.edu/sims/html/ resistance-in-a-wire/latest/resistance-in-a- wire_en.html https://phet.colorado.edu/sims/html/resistance-in-a-wire/latest/resistance-in-a-wire_en.html https://phet.colorado.edu/sims/html/resistance-in-a-wire/latest/resistance-in-a-wire_en.html https://phet.colorado.edu/sims/html/resistance-in-a-wire/latest/resistance-in-a-wire_en.html https://phet.colorado.edu/sims/html/resistance-in-a-wire/latest/resistance-in-a-wire_en.html College Physics II Resistor configurations EPCC Objective: Understand how resistors in series and parallel work. The LED bulbs will act as resistors, while the illuminance from the bulbs will be a proxy for current intensity in the circuit. Review Ohm’s law for this lab. Refer to the laboratory lecture to complete this laboratory. Note: Measurements must be in MKS units. Circuits 1. Simple circuit: Replicate the circuit described in figure 1, as well as draw the circuit diagram for this circuit. Activate the PhyPhox® app and select the “simple” function as shown in figure 2. Place the phone with PhyPhox running 1.0 cm from the edge of the circuit. Record the illuminance in table 1. 2. Parallel circuit: Replicate the circuit described in figure 2, as well as draw the circuit diagram for it. Follow the same procedure to record the illuminance, and record this value in table 1. Make a note what occurs after you remove one of the bulbs from the circuit. 3. Series circuit: Replicate the circuit described in figure 3, as well as draw the circuit diagram for it. Follow the same procedure to record the illuminance if you can; record this value in table 1. Table 1. Configuration Illuminance (lux) Simple Circuit Parallel Series click to record Figure 1: Screen shot of PhyPhox® Light function. Select the 'simple' option and click the play button to begin recording. Read off the values illuminance and record in table 1. College Physics II Resistor configurations EPCC Questions (Answer within 3 sentences): 1. How does the parallel circuit relate to the simple-circuit case? 2. Based on the series circuit results, what can you say about the current needed to light both bulbs? Does this explanation fit what you would expect from resistors in series? (a) (b) (c) Figure 2: Simple circuit for one LED bulb. (a): A minimum of two conductive strips each a length of 6.0 cm is needed. The battery is placed at the left end, with the corner able to flip to complete the circuit once the bulb is attached (b). The bulb turns on once the circuit is complete (c). Figure 3: Parallel circuit: An additional bulb is placed at the further along the two conductive strips, fastened with masking tape. Figure 4: Series circuit: replace the bulbs such that they are touching each other, and the other end of each bulb is connected to the conductive strip.