Series & parallel circuit measurements Part I

Transcription

1 Series parallel calculations sheet #1 Complete these problems below using your calculator. Both partners need to work the problems and agree on the answers. Record your answers below and analyze the work you did. Come up with ideas as to how the total resistance, current, or voltage in each type of circuit (series and parallel). Problem #1 V t = R t = I t = I R1 = V R1 = I R2 = V R2 = Problem #2 V t = R t = I t = I R1 = V R1 = I R2 = V R2 = Problem #3 V t = R t = I t = V R1 = I R1 = Problem #4 V t = R t = I t = V R1 = I R1 = V R2 = I R2 = Series & parallel circuit measurements Part I V R3 = I R3 = V R2 = I R2 = V R3 = I R3 =

2 Instructions: Teamwork is very important so show it in your work. Using the problems & data on the Series parallel calculations sheet #1 page, construct one hypothesis statement for series circuits, and one for parallel resistance circuits from the data you gathered. This statement will need to be focused on the properties of the circuits that you observed and their characteristics. Both teammates need to construct this and agree on the wording before it is written down. Once completed, raise your hand and you will begin the lab when you receive the packet and lab kit. Hypothesis #1 (series resistance circuit): Hypothesis #2 (parallel resistance circuit):

3 Series & Parallel Lab #1 Instructions: Complete this lab after completing the Series Parallel Calculations sheet. Construct the following circuits using the directions, pictures from the webpage, and handouts. Use the instructions to complete the Lab Data Sheet. Circuit #1 Note: remember that the breadboard is setup with parallel lines that will connect anything inserted into that row. In saying that, remember that electricity travels the path of least resistance if there is a short. There is a break between the columns that separates the rows or lines. Refer to the files on the webpage of you get confused. Diagram #1 Diagram #2 Using the breadboard, 1 battery, 1 battery holder, jumper wires, and resistors of the appropriate value, construct the circuit pictured in Diagram #1 but do not insert the battery. Diagram #2 is a picture of how the resistors and jumpers are configured on a breadboard for parallel resistance circuits. Parts: 1 AA battery holder 1 AA battery Ω resistor (color bands left to right - Red, Black, Brown, Gold)

4 1-330 Ω resistor (color bands left to right Orange, Orange, Brown, Gold) Jumper wires as needed 1 Volt/Ohm Multimeter(VOM) Procedure: 1. DO NOT CONNET THE BATTERY HOLDER IN THE CIRCUIT YET!!!!!! Wait until directed to hook the battery holder up. Assemble the circuit and raise your hand for questions or when completed. Make sure both students check the work several times before raising your hand. Remember this is TEAMWORK. 1.1 Pay attention to each resistor s color code and position on the schematic. Cross check what you measure vs what the schematic says to make sure you are measuring R1 or R2. Turn the VOM dial to Ohms and the scale closest to 330Ω but not under that value. Measure each resistor before putting them in the breadboard and record their actual measured value on the Lab Data sheet problem #1 chart. 1.2 Insert the top 330Ω resistor into the breadboard as shown. Do not force it. The legs should not bend if you hold it correctly. 1.3 Insert the bottom 200Ω resistor without forcing it in. 1.4 Insert the right jumper leg so that the top leg of the jumper is beside the right leg of the 330Ω resistor. 1.5 Insert the same jumper but the lower portion or leg needs to be inserted next to the 200Ω resistor as pictured. 1.6 Insert the left upper jumper next to the left side of the 330Ω resistor 1.7 Insert the same jumper - lower leg - next to the left side of the 220Ω resistor. 1.8 Insert the 2 jumpers labeled total resistance test points 2. Turn on the VOM by turning the dial to the resistance section of the dial. The 200 or 2000 ohm selection should be good enough, but you will need to decide which scale is the best for the answer. 2.1 Put the VOM probes on the breadboard to measure total resistance by lightly pressing the probe tips against the total resistance test points against the breadboard or your fingertips. Let the numbers settle till you can see a final measurement. Record your data on Lab Data Sheet for the total resistance. 2.2 Have your partner measure the total resistance to make sure the measurement is the same or approximately the same. 3. Take the battery holder and insert the leads (red (+) and black (-) where you see the probes touching in Diagram #2. 4. Turn the volt/ohm VOM dial to DC volts. This is represented by a V and a flat line with a dashed line below it. Put it on 20 volt or lower setting. Insert the battery into the battery

5 holder correctly. Measure and record the total voltage by pressing the probes to the battery leads or the holes next to them, then measure the voltage of each resistor by pressing the probes against the side of each resistor s legs. Remember the rules of a parallel circuit? Is the voltage the same? Write the total voltage on the data sheet then remove the probes. Record total voltage of the battery(v T ) as well as across each resistor (V R1 & V R2 ). 5. Due to the intrusive nature of measuring current, calculate currents based on the numbers that you have on the data sheet. Use a separate sheet of paper for scratch paper and your calculator if needed. We will demonstrate measuring current at the end of the lesson for the class to see. 6. Turn the VOM off and remove the battery from the holder. Remove all parts and put them in the bag or box. Circuit #2 Using the breadboard, 1 battery, 1 battery holder, jumper wires, and resistors of the appropriate value, construct the circuit pictured. Diagram #3 is the circuit that you need to build. Diagram #4 is a picture of how the resistors are configured on a breadboard for series resistance circuits. Diagram #3 3 Parts: 1 AA battery holder 1 AA battery Ω resistor (color bands left to right - Red, Black, Brown, Gold) Ω resistor (color bands left to right Brown, Black, Brown, Gold) Diagram #4 Jumper wires as needed 1 Volt/Ohm Multimeter(VOM)

6 Procedure: 1. DO NOT CONNET THE BATTERY HOLDER IN THE CIRCUIT YET!!!!!! Wait until directed to hook the battery holder up. Assemble the circuit and raise your hand for questions or when completed. Make sure both students check the work several times before raising your hand. Remember this is TEAMWORK. 1.1 Pay attention to each resistor s color code and position on the schematic. Cross check what you measure vs what the schematic says to make sure you are measuring R1 or R2. Turn the VOM dial to Ohms and the scale closest to 330Ω but not under that value. Measure each resistor before putting them in the breadboard and record their actual measured value on the Lab Data sheet problem #2 chart. 1.2 Insert the top 200Ω resistor into the breadboard as shown. Do not force it. The legs should not bend. 1.3 Insert the bottom 100Ω resistor without forcing it in. 1.4 Insert the right jumper leg so that the top leg of the jumper is beside the right leg of the 200Ω resistor. 1.5 Insert the same jumper but the lower portion or leg needs to be inserted next to the 100Ω resistor as pictured. 1.6 Insert the left upper jumper next to the left side of the 200Ω resistor 1.7 Insert the same jumper lower leg next to the left side of the 100Ω resistor. 1.8 Insert the 2 jumpers labeled total resistance test points 2. Turn the VOM resistance or Ω label at a scale of close to but not under 200Ω s. 2.1 Put the VOM probes on the breadboard to measure total resistance by lightly pressing the probe tips against the total resistance test points against the breadboard or your fingertips. Let the numbers settle till you can see a final measurement. Record your data on Lab Data Sheet for the total resistance. Have your partner double check the measurement by doing it themselves. 2.2 Have your partner measure the total resistance to make sure the measurement is the same or approximately the same. 3. Take the battery holder and insert the leads (red (+) and black (-) where you see the probes touching in Diagram #4. 4. Turn the volt/ohm VOM dial to DC volts. This is represented by a V and a flat line with a dashed line below it. Put it on 20 volt or lower setting. Insert the battery into the battery holder correctly. Measure and record the voltage by pressing the probes to the battery leads or in the holes next to the battery leads on the breadboard - record the

7 data for (V T ). Then measure the voltage for each resistor by pressing the probes against the side of each resistor set and record the data for each one (V R1 & V R2 ). Remember the rules of a parallel circuit? Is the voltage the same? 5. Due to the intrusive nature of measuring current, calculate currents based on the numbers that you have on the data sheet. Use a separate sheet of paper for scratch paper and your calculator if needed. We will demonstrate measuring current at the end of the lesson for the class to see. Circuit #3 Using the breadboard, 1 battery, 1 battery holder, jumper wires, and resistors of the appropriate value, construct the circuit pictured. Diagram #5 is the circuit that you need to build. Diagram #6 is a picture of how the resistors are configured on a breadboard for series resistance circuits. Diagram #5 Parts: 1 AA battery holder 1 AA battery Ω resistor (color bands left to right - Red, Black, Brown, Gold or Silver) Ω resistor (color bands left to right Orange, Orange, Brown, Gold or Silver) Jumper wires as needed 1 Volt/Ohm Multimeter(VOM) Diagram #6 Procedure: 1. DO NOT CONNET THE BATTERY HOLDER IN THE CIRCUIT YET!!!!!! Wait until directed to hook the battery holder up. Assemble the circuit and raise your hand for questions or

8 when completed. Make sure both students check the work several times before raising your hand. Remember this is TEAMWORK. 2. Pay attention to each resistor s color code and position on the schematic. Cross check what you measure vs what the schematic says to make sure you are measuring R1, R2 or R3. Turn the VOM dial to Ohms and the scale closest to 330Ω but not under that value. Measure each resistor before putting them in the breadboard and record their actual measured value on the Lab Data sheet problem #3 notes section. 2.1 Insert R1-200Ω into the breadboard as shown in Diagram #6. Do not force the resistor into the hole with too much force. Use your fingers and hold it where it will not bend. Do this for all other resistors as well. 2.2 Insert R2-200Ω into the breadboard as shown in Diagram # Insert R3-330Ω into the breadboard as shown in Diagram # Insert Jumper #1 so that R1 and R2 are connected as shown in Diagram # Insert Jumper #2 so that R2 and R3 are connected as shown in Diagram # Insert the Total Resistance Test Leads into the positions shown in Diagram #6. 3. Turn the VOM resistance or Ω label at a scale of close to but not under 1000Ω s Put the VOM probes on the breadboard to measure total resistance by lightly pressing the probe tips against the total resistance test points against the breadboard or your fingertips. Let the numbers settle till you can see a final measurement. Record your data on the Lab #1 Data Sheet for the total resistance. Have your partner double check your measurement by doing it themselves. 4. While analyzing diagram #6 place the battery holder leads (red and black) into the circuit to apply power 5. Turn the volt/ohm VOM dial to DC volts. This is represented by a V and a flat line with a dashed line below it. Put it on 20 volt setting. Insert the battery correctly in the battery holder. Measure and record the total voltage by pressing the probes lightly into the holes nest to the battery leads or against the battery leads inserted into the breadboard. Record the total voltage on the Lab Data Sheet. Then measure the voltage across each resistor by lightly pressing the probes against the base of the legs for each resistor and record the data on the Lab Data Sheet. Remember the rules of a series circuit? Is the voltage the same? 6. Due to the intrusive nature of measuring current, calculate current based on the numbers that you have on the data sheet. Use a separate sheet of paper for scratch paper and your calculator if needed. We will demonstrate measuring current at the end of the lesson for the class to see.

9 Circuit #4 Using the breadboard, 1 battery, 1 battery holder, jumper wires, and resistors of the appropriate value, construct the circuit pictured. Diagram #7 is the circuit that you need to build. Diagram #8 is a picture of how the resistors are configured on a breadboard for series resistance circuits. Diagram #7 Parts: 1 AA battery holder 1 AA battery Ω resistor (color bands left to right - Red, Black, Brown, Gold or Silver) Ω resistor (color bands left to right Orange, Orange, Brown, Gold or Silver) Diagram #8 Procedure: 1. DO NOT CONNET THE BATTERY HOLDER IN THE CIRCUIT YET!!!!!! Wait until directed to hook the battery holder up. Assemble the circuit and raise your hand for questions or when completed. Make sure both students check the work several times before raising your hand. Remember this is TEAMWORK. 2. Pay attention to each resistor s color code and position on the schematic. Cross check what you measure vs what the schematic says to make sure you are measuring R1, R2 or R3. Turn the VOM dial to Ohms and the scale closest to 330Ω but not under that value. Measure each resistor before putting them in the breadboard and record their actual measured value on the Lab Data sheet problem #3 notes section. 2.1 Insert R1-330Ω into the breadboard as shown in Diagram #6. Do not force the resistor into the hole with too much force. Use your fingers and hold it where it will not bend. Do this for all other resistors as well. 2.2 Insert R2-200Ω into the breadboard as shown in Diagram #6.

10 2.3 Insert R3-330Ω into the breadboard as shown in Diagram # Insert Jumper #1 so that R1 and R2 are connected as shown in Diagram # Insert Jumper #2 so that R2 and R3 are connected as shown in Diagram # Insert the Total Resistance Test Leads into the positions shown in Diagram #6. 3. Turn the VOM resistance or Ω label at a scale of close to but not under 1000Ω s Put the VOM probes on the breadboard to measure total resistance by lightly pressing the probe tips against the total resistance test points against the breadboard or your fingertips. Let the numbers settle till you can see a final measurement. Record your data on the Lab #1 Data Sheet for the total resistance 4. While analyzing diagram #6 place the battery holder leads (red and black) into the circuit to apply power 5. Turn the volt/ohm VOM dial to DC volts. This is represented by a V and a flat line with a dashed line below it. Put it on 20 volt setting. Insert the battery into the battery holder correctly. Measure and record the total voltage by pressing the probes lightly into the holes nest to the battery leads or against the battery leads inserted into the breadboard. Record the total voltage on the Lab Data Sheet. Then measure the voltage across each resistor by lightly pressing the probes against the base of the legs for each resistor and record the data on the Lab Data Sheet. Remember the rules of a series circuit? Is the voltage the same? Write the total voltage on the data sheet then remove the probes. Measure the voltage across each resistor and record it. 6. Due to the intrusive nature of measuring current, calculate current based on the numbers that you have on the data sheet. Use a separate sheet of paper for scratch paper and your calculator if needed. We will demonstrate measuring current at the end of the lesson for the class to see.

11 Lab Data Sheet #1 Record the data from the lab experiment on this sheet. Follow all directions as diected. Ask questions if need help. Problem #1 Measured Value of: Problem #1 Measured Value of: V t = R1 in Ω: R t = R2 in Ω: I t = V R1 = I R1 = V R2 = I R2 = Notes: V t = R1 in Ω: R t = R2 in Ω: I t = V R1 = I R1 = V R2 = I R2 = Notes: Problem #3 Measured Value of: Problem #4 Measured Value of: V t = R1 in Ω: R t = R2 in Ω: I t = R3 in Ω: V R1 = I R1 : V R2 = I R2 : V R3 = I R3 : Notes: V t = R1 in Ω: R t = R2 in Ω: I t = R3 in Ω: V R1 = I R1 : V R2 = I R2 : V R3 = I R3 : Notes: Continue on to Lab Data Sheet #2

12 Lab data Sheet #2 Parallel Circuit section refer back to your hypothesis statement - (There are no I don t know answers allowed) Did you prove your statement (yes or no)? What was the critical measurement that affected your statement? Were the resistors the same as the value on the schematic? (Yes or No) Why would the resistors be different than what they were sold as? Why were the figures from the paper series/parallel circuit sheet slightly different than those in the lab? Using the following formula, double check your V T. Parallel R T =(R1*R2)/(R1+R2) Problem #1 Answer: Ω Does it match the V T on the lab sheet #1? Problem #2 Answer: Ω Does it match the V T on the lab sheet #2? Is the total resistance in a parallel circuit always going to be less than the lowest resistor value? Why? What did you learn about parallel resistance or parallel circuits from this exercise? - If you liked the lab and will accept a math challenge, ask me for the Bonus lab sheet.

13 Series Circuit section refer back to your hypothesis statement - (There are no I don t know answers allowed) Did you prove your statement (yes or no)? What was the critical measurement that affected your statement? Were the resistors the same as the value on the schematic? (Yes or No) Was Series VT the sum of the individual parts? Prove it with your results: Why would the resistors be different than what they were sold as? Why were the figures from the paper series/parallel circuit sheet slightly different than those in the lab? What did you learn about series resistance or series circuits from this exercise?