Includes Teacher's Notes and Typical Experiment Results Instruction Manual and Experiment Guide for the PASCO scientific Model EM-8622 012-04367E 4/94 BASIC ELECTRICITY L DE MO -8622 EM C B CW A D E - + + C © 1990 PASCO scientific $10.00 better 10101 Foothills Blvd. • P.O.
012-04367E Basic Electricity Table of Contents Section ...........................................................................................................Page Copyright, Warranty, and Equipment Return ................................................. ii Introduction ..................................................................................................... 1 Equipment ........................................................................................................
Basic Electricity 012-04367E Copyright, Warranty and Equipment Return Please—Feel free to duplicate this manual subject to the copyright restrictions below. Copyright Notice Equipment Return The PASCO scientific Model EM-8622 Basic Electricity manual is copyrighted and all rights reserved. However, permission is granted to non-profit educational institutions for reproduction of any part of this manual providing the reproductions are used only for their laboratories and are not sold for profit.
012-04367E Basic Electricity Introduction The PASCO Circuits Experiment Board is designed to implement a large variety of basic electrical circuits for experimentation. The Circuits Experiment Board can be used for experiments beginning with a simple complete circuit and continuing on to a study of Kirchhoff’s Laws and characteristics of diodes and transistors. A labeled pictorial diagram of the Experiment Board appears in Figure 1.2 of Experiment 1.
Basic Electricity 012-04367E Getting Started ➀ Open the zip-lock bag containing the resistors and Store the remainder of the components in the ziplock bag until needed in future experiments. other components. Distribute the following resistors and wires to each of the boards, storing them in the plastic holder at the top of the board: ➁ Students will need to use the same resistors, same batteries, etc. from one experiment to another, particularly during experiments 4 to 6.
012-04367E Basic Electricity Comments on Meters VOM: VTVM: The Volt-Ohm-Meter or VOM is a multiple scale, multiple function meter (such as the PASCO SB-9623 Analog Multimeter), typically measuring voltage and resistance, and often current, too. These usually have a meter movement, and may select different functions and scales by means of a rotating switch on the front of the unit. The Vacuum Tube Voltmeter or VTVM is a multiple scale, multiple function meter, typically measuring voltage and resistance.
Basic Electricity 012-04367E Notes on the Circuits Experiment Board The springs are securely soldered to the board and serve as a convenient method for connecting wires, resistors and other components. Some of the springs are connected electrically to devices like the potentiometer and the D-cells. In the large Experimental Area, the springs are connected in pairs, oriented perpendicular to each other. This facilitates the connection of various types of circuits.
012-04367E Basic Electricity Experiment 1: Circuits Experiment Board EQUIPMENT NEEDED: -Circuits Experiment -D-cell Battery -Graph -Board -Wire Leads -Paper Purpose The purpose of this lab is to become familiar with the Circuits Experiment Board, to learn how to construct a complete electrical circuit, and to learn how to represent electrical circuits with circuit diagrams. Background ➀ Many of the key elements of electrical circuits have been reduced to symbol form.
Basic Electricity 012-04367E Procedure ➀ Use two pieces of wire to make connections between the springs on one of the light bulbs to the springs on the D-cell in such a way that the light will glow. Discuss with your lab partner before you begin actually wiring your circuit which connections you intend to make, and why you think you will be successful in activating the light.
012-04367E Basic Electricity Experiment 2: Lights in Circuits EQUIPMENT NEEDED: -Circuits Experiment Board -Wire Leads -Two D-cell Batteries -Graph Paper. Purpose The purpose of this lab is to determine how light bulbs behave in different circuit arrangements. Different ways of connecting two batteries will also be investigated.
Basic Electricity 012-04367E PART B ➆ Connect a single D-cell to a single light as in step 1, using a spring clip “switch” to allow you to easily turn the current on and off. Note the brightness of the light. ⑧ Now connect the second D-cell into the circuit as shown in Figure 2.1a. What is the effect on the brightness of the light? ➤ ➤ ➤ ➤ ➤ ➤ Figure 2.1a Figure 2.1b Figure 2.1c ⑨ Connect the second D-cell as in Figure 2.1b.
012-04367E Basic Electricity Experiment 3: Ohm’s Law EQUIPMENT NEEDED: -Circuits Experiment Board -Multimeter -Graph Paper. -D-cell Battery -Wire Leads Purpose The purpose of this lab will be to investigate the three variables involved in a mathematical relationship known as Ohm’s Law. Procedure ➀ Choose one of the resistors that you have been given. Using the chart on the back, decode the resistance value and record that value in the first column of Table 3.1.
Basic Electricity 012-04367E Data Processing ➀ Construct a graph of Current (vertical axis) vs Resistance. ➁ For each of your sets of data, calculate the ratio of Voltage/Resistance. Compare the values you calculate with the measured values of the current. Resistance, Ω Current, amp Voltage, volt Voltage/Resistance Table 3.1 Discussion ➀ From your graph, what is the mathematical relationship between Current and Resistance? ➁ Ohm’s Law states that current is given by the ratio of voltage/resistance.
012-04367E Basic Electricity Experiment 4: Resistances in Circuits EQUIPMENT NEEDED: -Circuits Experiment Boar - Multimeter -Resistors. Purpose The purpose of this lab is to begin experimenting with the variables that contribute to the operation of an electrical circuit. This is the first of a three connected labs. Procedure ➀ Choose the three resistors having the same value. Enter those sets of colors in Table 4.1 below. We will refer to one as #1, another as #2 and the third as #3.
Basic Electricity 012-04367E Series R1 R2 R3 R12= R23= ➤ R12 ➤ ➤ ➤ R23 R123= ➤ ➤ R123 Figure 4.1 ➅ Construct a PARALLEL CIRCUIT, first using combinations of two of the resistors, and then using all three. Measure and record your values for these circuits. Parallel R1 ➤ NOTE: Include also R13 ➆ Connect the COMBINATION ➤ CIRCUIT below and measure the various combinations of resistance.
012-04367E Basic Electricity 1st Colors 2nd 3rd Coded Measured 4th Resistance Resistance % Error A B C Table 4.2 Series RA RB RC RAB = RAB RBC = ➤ RBC ➤ ➤ RABC ➤ ➤ ➤ Figure 4.4 Parallel RA RAB RAB = ➤ ➤ RBC = RB RABC= RC Figure 4.
Basic Electricity 012-04367E Combination RB RA RA = RC RBC = ➤ ➤ RA ➤ ➤ RBC RABC RABC= ➤ Figure 4.6 Discussion ➀ How does the % error compare to the coded tolerance for your resistors? ➁ What is the apparent rule for combining equal resistances in series circuits? In parallel circuits? Cite evidence from your data to support your conclusions.
012-04367E Basic Electricity Experiment 5: Voltages in Circuits EQUIPMENT NEEDED: -Circuits Experiment Board -D-cell Battery -Wire Leads -Multimeter -Resistors Purpose The purpose of this lab will be to continue experimenting with the variables that contribute to the operation of an electrical circuit. You should have completed Experiment 4 before working on this lab.
Basic Electricity 012-04367E ➂ Now connect the parallel circuit below, using all three resistors. Measure the voltage across each of the resistors and the combination, taking care with the polarity as before. ➤NOTE: Keep all three resistors connected throughout the time you are making your measurements. Write down your values as indicated below. Parallel + - ➤ ➤ R1 R1 = V1 = R2 = V2 = R3 = V3 = R123 = V123 = V1 R2 R3 Figure 5.2 ➃ Now connect the circuit below and measure the voltages.
012-04367E Basic Electricity Series + - VA + RA RC RB - + - + - + ➤ ➤ VAB ➤ VBC VABC ➤ ➤ ➤ Figure 5.4 RA = VA = RB = VB = RC = VC = RAB = VAB = RBC = VBC = RABC= VABC= Parallel + - ➤ ➤ RA VA RB RA = VA = RB = VB = RC = VC = RABC= VABC= RC Figure 5.
Basic Electricity 012-04367E Combination + - RA = VA = RBC = VBC = RABC= VABC = RB RA RC ➤ VA ➤ VABC VBC ➤ ➤ ➤ ➤ Figure 5.6 Discussion On the basis of the data you recorded on the table with Figure 5.1, what is the pattern for how voltage gets distributed in a series circuit with equal resistances? According to the data you recorded with Figure 5.
012-04367E Basic Electricity Experiment 6: Currents in Circuits EQUIPMENT NEEDED: -Circuits Experiment Board -Resistors -Wire Leads. -Digital Multimeter -D-cell Battery Purpose The purpose of this lab will be to continue experimenting with the variables that contribute to the operation of electrical circuits.
Basic Electricity 012-04367E - I0 + + R1 - + - I 2 R3 R2 + I1 + - I3 - Figure 6.3 R1 = I0 = V1 = R2 = I1 = V2 = R3 = I2 = V3 = R12 = I3 = V12 = R23 = V23 = R123= V123= ➃ Connect the parallel circuit below, using all three resistors. Review the instructions for connecting the DMM as an ammeter in step 2. Connect it first between the positive terminal of the battery and the parallel circuit junction to measure I0.
012-04367E Basic Electricity Experiment 7: Kirchhoff’s Rules EQUIPMENT NEEDED: -Circuits Experiment Board -Wire Leads -Resistors. -Two D-cell Batteries -Digital Multimeter (DMM) Purpose The purpose of this lab will be to experimentally demonstrate Kirchhoff’s Rules for electrical circuits. Procedure ➀ Connect the circuit shown in Figure 7.1a using any of the resistors you have except the 10 Ω one. Use Figure 7.1b as a reference along with 7.1a as you record your data.
Basic Electricity 012-04367E Resistance, Ω Voltage, volts Current, mA R1 V1 I1 R2 V2 I2 R3 V3 I3 R4 V4 I4 R5 V5 I5 RT VT IT Table 7.1 Analysis ➀ Determine the net current flow into or out of each of the four “nodes” in the circuit. ➁ Determine the net voltage drop around at least three (3) of the six or so closed loops. Remember, if the potential goes up, treat the voltage drop as positive (+), while if the potential goes down, treat it as negative (-).
012-04367E Basic Electricity Experiment 8: Capacitors in Circuits EQUIPMENT NEEDED: – Vacuum Tube Voltmeter (VTVM) or Electrometer (ES-9054B) or Digital Multimeter (DMM) that has an input impedance of 10 MΩ or greater. – Circuits Experiment Board – Capacitors, Resistors – Wire Leads – D-cell Battery – Stopwatch or timer with 0.1 sec resolution. Purpose The purpose of this lab will be to determine how capacitors behave in R-C circuits. The manner in which capacitors combine will also be studied.
Basic Electricity 012-04367E Trial Resistance Capacitance tC tD 1 2 3 4 5 6 7 8 Table 8.1 ⑧ Replace the 100-µF capacitor with a 330-µF capacitor. Repeat step 7, recording the charging and discharging times in Table 8.1. If a third value is available, include it in the data table, too. ⑨ Return to the original 100-µF capacitor, but put a 220-K Ω resistor in the circuit. Repeat step 7, recording your data in Table 8.1. If a third resistor is provided, use it in the circuit, recording the data.
012-04367E Basic Electricity Experiment 9: Diodes EQUIPMENT NEEDED: -Circuits Experiment Board -Wire Leads -1000-Ω Resistor -330-Ω Resistor. -Digital Multimeter (DMM) -Two D-cell Batteries -1N4007 Diode Purpose The purpose of this lab will be to experimentally determine some of the operating characteristics of semiconductor diodes. Procedure ➀ Connect the circuit shown in Figure 9.1a using the 1N4007 diode you’ve been supplied and the 1000-Ω resistor. Use Figure 9.
Basic Electricity 012-04367E Discussion Discuss the shape of your graph and what it means for the operation of a semiconductor diode. Did the diode operate the same in steps 3 and 4 as it did in step 5? In steps 3 and 4 the diode was “Forward Biased”, while it was “Reverse Biased” in step 5.
012-04367E Basic Electricity Experiment 10: Transistors EQUIPMENT NEEDED: -Circuits Experiment Board -Wire Leads -1000-Ω Resistor -100-Ω Resistor. -Two D-cell Batteries -Digital Multimeter (DMM) -2N3904 Transistor (NPN) Purpose The purpose of this lab will be to experimentally determine some of the operating characteristics of a transistor. Procedure ➀ Connect the circuit shown in Figure 10.1a using the 2N3904 Transistor you’ve been supplied. Resistor R1 = 1000 Ω and resistor R2 = 100 Ω.
Basic Electricity 012-04367E Analysis ➀ For each of your sets of readings, calculate: IB = VAB / R1 and IC = VCD / R2 Record all of your current readings in mA. ➁ Plot a graph of IC (vertical axis) vs IB. If you find an area or areas where you need more points to fill out any curves or sudden changes, simply return to step 2 and make the appropriate measurements.
012-04367E Basic Electricity Appendix: Tips and Troubleshooting Correct Circuit, Doesn’t Work The labs asking for relative brightness ask students to judge relative brightness only, not an absolute brightness. This part of the experiment would be aided by having the room mostly darkened. Additional bulbs can be purchased from PASCO, at Radio Shack, an electronics store, at auto supplies stores, or possibly a local discount store.
Basic Electricity 012-04367E Wires Pulling the wire away from the stripper (Figure 3c) causes the cut end of the insulation to slip off of the wire, leaving 3/8" of exposed wire. The Circuits Experiment Board can be used with a large variety of wire types and sizes. We recommend 20 or 22 gauge solid wire with colorful insulation.
012-04367E Basic Electricity Replacement Parts List Item PASCO Part # P.C.B.
Basic Electricity 012-04367E Notes 32
012-04367E Basic Electricity Teacher's Guide Exp 1 - Circuits Experiment Board ➀ With this method, the lights will each be approximately the same brightness as in part 1. Serial: ➁ Reversing things at either end had no effect. ➃➄ There are two different ways of putting two lamps into the circuit: parallel and serial. Parallel: Using this circuit, the lights will be dimmer than in part 1. Exp 2 - Lights in Circuits ➃➄ ➤NOTE: It is best to do these experiments with both batteries, rather than just one.
Basic Electricity 012-04367E Exp 3- Ohm's Law Procedure 0.16 ➁-➅)Warn the students to be particularly careful when 0.14 setting up the multimeter to measure current. Attaching an ammeter the wrong way can damage the meter. Current 0.12 Data Processing Resistance 100 560 330 1000 10 Current 0.02 0.00 0.00 0.00 0.14 Voltage 1.579 1.582 1.582 1.583 1.549 J V/R % difference 0.02 -1.87% 0.00 -2.73% 0.00 -3.32% 0.00 -9.17% 0.15 -13.31% 0.1 0.08 0.06 0.04 0.
012-04367E Basic Electricity Colors A brown-black-brown-gold B orange-orange-brown-gold C green-blue-brown-gold coded 100 330 560 measured 98.9 330 561 % error -1.10% 0.00% 0.18% tolerance ±0.05% ±0.05% ±0.05% ➁-➃ In series, the resistances are added. R = R1 + R2 + R3 + ...In parallel, the reciprocals of the resistances are added. 1/R = 1/R1 + 1/R2 + 1/R3 +... This is evidenced in all the data sets above.
Basic Electricity 012-04367E Exp 6- Currents in Circuits ➤NOTE: R1 = R2 = R3 = The resistors used were: Discussion 100Ω 330Ω 560Ω In any resistance circuit—series, parallel, or both—the voltage, current, and resistance are related by Ohm’s Law: V = IR These are the same resistors as were used in the previous lab, and some of the data here originates in lab 5. This pattern, and conclusion, should be apparent in student data.
012-04367E Basic Electricity Analysis Second circuit: First circuit: ➀ node (2,3,4): ➀ node (1,3): -0.1 mA 0.1 mA node (b1,3,5): 0.1 mA node (1,2,5): 0.0 mA ➁ loop (b1,1,2,3) 0.001 V node (3,4,5): -0.1 mA loop (b2,5,3,4) 0.001 V node (2,4): 0.0 mA loop (b1,1,2,4,b2,5) 0.002 V ➁ loop (1,5,3): 0.001 V loop (1,2,4,3): 0.001 V loop (5,2,4): 0.000 V loop (batt,1,2): 0.001 V loop (batt,3,4): 0.000 V loop (batt,1,5,4): 0.001 V loop (batt,3,5,2): 0.
Basic Electricity 012-04367E Exp 9- Diodes Analysis The diode acts as a one-way valve for electricity. Current can flow in one direction, but not in the other. 0.007 Extensions 0.006 0.005 4007 J J LED J O ➀ A zener diode would be similar to the 4007, except that there would be a breakdown point on the reverse biasing, beyond which the current would flow. This makes them useful for power regulation. Current J O 0.004 J 0.003 0.002 0.
012-04367E Basic Electricity Technical Support Feed-Back Contacting Technical Support If you have any comments about this product or this manual please let us know. If you have any suggestions on alternate experiments or find a problem in the manual please tell us. PASCO appreciates any customer feedback. Your input helps us evaluate and improve our product.
