Lab 6 Resistance in a Wire-asa

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Feb 20, 2024

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Lab 6: Resistance in a Wire © 2023 by Orlando Patricio adapted from https://phet.colorado.edu/en/simulations/category/physics Name: Asael Garcia INSTRUCTIONS: (1) Download this lab document, CLICK on “ enable editing ” located at the top, middle of the downloaded document and type out answers on the space provided for then save your answers. (2) If the spacing automatically moves, adjust so that your answers are not all over the place. (3) Upload this document, with your answers on it, on the designated Lab 6 Dropbox on Canvas Lab Reports/Module Tab. (4) If possible, ALL answers must be in green font or highlighted in yellow background with black font. Grading Policy for Lab Reports WITH Pre-/Post-lab Questions Grading Policy for Lab Reports WITHOUT Pre-/Post-lab Questions Completeness and accuracy of answers (with required screenshots) for the: 1. Warm-up and lab activities – 70% 2. Pre-/Post-lab questions – 10% 3. Conclusions and real-life applications – 20% Completeness and accuracy of answers (with required screenshots) for the: 1. Warm-up and lab activities – 80% 2. Conclusions & real-life applications – 20% This lab uses the Resistance in a Wire and Circuit Construction Kit: DC simulation from PhET Interactive Simulations at University of Colorado Boulder, under the CC-BY 4.0 license. Purposes/Objectives: In this lab, you will be able to: 1) explore the characteristics or factors that affect the resistance of a conductor or wire. 2) identify how each characteristic affects the resistance and current flow. 3) explain your ideas about why the characteristics change the resistance and current flow. 4) make predictions about a circuit with lights and batteries. Procedure: A. Develop your understanding: 1) Click the link below (hover mouse on the link then press at the same time: ctrl and left click ) https://phet.colorado.edu/sims/html/resistance-in-a-wire/latest/resistance-in-a-wire_en.html 2) Open Resistance in a Wire . Explore to develop your own ideas about how the construction of a resistor affects its resistance and ability to allow current to flow. Your screen should look like the one below.

Lab 6: Resistance in a Wire © 2023 by Orlando Patricio adapted from https://phet.colorado.edu/en/simulations/category/physics 3) Explore using the sliders for resistivity, length, and (cross-section) area. The control panels are located on the right side of the lab area. The circular orange button at the bottom right corner is the Reset button. What did you discover? Write your answers below. Also, paste below screenshot to support your answers. B. Demonstrate your understanding: As you answer the following questions, explain in your own words why your answer makes sense and provide evidence (screenshot) from your #3 experiment/activity. Add more experiments to #3 if you need better evidence. 4) If you change the cross-sectional area (thickness) of the resistor, a) how does the resistance changes? (answer, explain, evidence or screenshot) I learned that as you increase length and resistivity, the resistance also increases with it. On the other hand, when you increase the area, the resistance decreases. .

Lab 6: Resistance in a Wire © 2023 by Orlando Patricio adapted from https://phet.colorado.edu/en/simulations/category/physics b) how does the current through a circuit change? (answer, explain, evidence or screenshot) Yous see that the current through the resistance loses power and slows down as the area gets bigger. The opposite happens when you make the area smaller. This means as the resistance decreases the current will increase. As you increase the area, the resistance decreases. Area is inversely proportional to resistance. .

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Lab 6: Resistance in a Wire © 2023 by Orlando Patricio adapted from https://phet.colorado.edu/en/simulations/category/physics 5) If you change the length of the resistor, a) how does the resistance changes? (answer, explain, evidence or screenshot) b) how does the current through a circuit change? (answer, explain, evidence or screenshot) The length and resistance are directly proportional to each other. That means as you increase the length, so does the resistance and vice versa. Here you see that as the resistance increase, that means the current will decrease. The reason for this the length is increasing mean there will be more resistance leading to less current.

Lab 6: Resistance in a Wire © 2023 by Orlando Patricio adapted from https://phet.colorado.edu/en/simulations/category/physics 6) If you change the resistivity (type of material) of the resistor, is the effect similar to changing the length or changing the cross-section area? (answer, explain, evidence or screen shot) 7) When manufacturing resistors, how is the resistivity of a resistor changed? Cite your references. The resistivity and resistance are directly proportional to each other. That means as you increase the resistivity, so does the resistance and vice versa. This effect is like changing the length. They are both directly proportional to resistance. During the manufacturing process, a resistor's resistivity can be modified by changing the material's composition and structure. Depending on the kind of resistor being made, the precise method used to alter the resistivity may differ, but it usually entails adding impurities or using particular heat treatments to affect the material's crystal structure. (n.d.). Wikipedia. Retrieved February 9, 2024, from https://www.electronicshub.org/resistors/

Lab 6: Resistance in a Wire © 2023 by Orlando Patricio adapted from https://phet.colorado.edu/en/simulations/category/physics C. Extend your understanding: 8) Consider the two circuits below in which the resistor on the left is 10.0  and the resistor on the right circuit is 30.0  . Check the resistance of the resistors. Use your understanding of Ohm’s law (relationship of voltage, resistance, and current) to answer the questions that follow: a) What do you think will happen when the switches are turned closed? (answer, explain, evidence or screenshot) The current will begin to flow and the light bulb will turn on.

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Lab 6: Resistance in a Wire © 2023 by Orlando Patricio adapted from https://phet.colorado.edu/en/simulations/category/physics b) Compare the brightness (current indicator) of the lightbulbs? c) Open the Intro screen of Circuit Construction Kit DC. https://phet.colorado.edu/sims/html/circuit-construction-kit-dc/latest/circuit-construction- kit-dc_en.html?screens=1 Build the 2 circuits similar to those in #8 and verify your answers. Insert a capture or screen shot of the circuits, in the box space provided below, with the switch closed for supporting evidence. Tips in building a circuit using this PhET sim: To build a circuit you will need several wires, light bulbs, resistors, voltage source, voltmeter, and non – contact ammeter. Drag and drop them into the lab area then connect the parts. Play with circuit elements to see how to grab and manipulate these tools. Remember to put a check mark on the Show Current , Labels , and Values on the control panel located at the top right corner of the lab area to see the electrons flowing through the wires and the resistance values will show on the screen. Tap a resistor. When a slider window will show, adjust the resistance as desired. If you want to get ahead. Pay attention how the voltmeter and ammeter are connected. Flip the polarity (terminal) of the voltmeter if the voltmeter reading displays a negative voltage. The negative terminal of the voltmeter must be connected close to the negative terminal of the battery while the positive terminal of the voltmeter with the positive end of the battery. Voltmeter is connected across or parallel to a circuit element while an ammeter is connected in series. In order to complete the circuit, the red circles at the end of each circuit element must overlap. Please note that the light bulb also has TWO circles. Your circuit is complete and working when the light comes on and the blue dots (electrons) begin moving. Hence, remember to close the switch to make the circuit work. To edit your circuit, tap the circuit and delete or add some circuit elements. The brightness is lower when there is a resistor added. The light bulb doesn’t shine as bright as it did without it.

Lab 6: Resistance in a Wire © 2023 by Orlando Patricio adapted from https://phet.colorado.edu/en/simulations/category/physics As you can see the resistors influence the current going into the light bulb. The resistors minimize the current making it work slower and shine less bright. The current can be seen numerically smaller as well.

Lab 6: Resistance in a Wire © 2023 by Orlando Patricio adapted from https://phet.colorado.edu/en/simulations/category/physics Post-Lab Questions: 1) What are the factors that affect the resistance of a conductor or wire? The factors are area, length, resistance, and temperature. 2) What is the relationship between current and resistance? They share an inverse relationship of each other. As one goes up, the other goes down. 3) Differentiate resistance and resistivity . Resistivity is a property of the material, while resistance depends on the amount, size, and shape of the material. Conclusions: Write a summary (explanations) of the physics concepts learned based from the results of the lab experiment. Elaborate. Provide real-life applications/examples. Through this lab we learned about Ohm’s law and what factors affect the resistance of it. The length, resistivity/material, area, and temperature all factor in the resistance of a wire. We also saw how resistance correlates to current inversely. As resistance increases, the current decreases. We saw this take place when we built our own source of light with the second part of the lab. The electrical connection containing the resistor shined with less light. In the real world we can use this when connecting electrical connections and knowing what affects them. You can add a resistor to make the light sign less brighter slowing down the electrical current. Besides that, you will also know what type of wire, shape, size, and length you should choose.

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