Ohm's Law

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Lab Report Experiment #3 – Simple DC Circuits In this experiment we learn to assemble a simple DC circuit and measure resistance using an ammeter and a voltmeter. A circuit is made using two resistors in various configurations. Readings are taken for the current at different voltages. From the resulting readings, the resistance of the resistors may be calculated. The resistance in the circuit can be measured using Ohm’s Law. Ohm’s Law states that the resistance through a conductor is directly proportional to the voltage and inversely proportional to the current. Using this equation we can find the experimental value for resistance. Apparatus DC power supply, DC voltmeter and ammeter, two unknown resistors mounted on a box (10–100 Ohms) Procedure Connect the circuit as shown in the diagram. Part A 1) Turn the power on and adjust the voltage to 2 volts. 2) Record the current though R1 and make four additional readings with different voltages. 3) Repeat the above steps with R2. Part B 1) Connect the resistors in series and make readings with at least three different voltages. Part C 1) Connect the resistors in parallel and make readings with at least three different voltages. Data / Analysis Part A R1 | | | | | Current (mA) | Voltage (V) | Resistance (Ohm) | | | | | 45.3 | 2.065 | 45.58 | | Average Resistance | 45.38 | 68.5 | 3.121 | 45.56 | | | | | 92.4 | 4.21 | 45.56 | | Standard Deviation | 0.26 | 111.6 | 5.03 | 45.07 | | | | | 136.5 | 6.16 | 45.13 | | | | | R2 | | | | | Current (mA) | Voltage (V) | Resistance (Ohm) | | | | | 81.5 | 2.001 | 24.55 | | Average Resistance | 23.43 | 130.1 | 3.039 | 23.36 | | | | | 181.3 | 4.16 | 22.95 | | Standard Deviation | 0.66 | 220.6 | 5.15 | 23.35 | | | | | 261.5 | 6.00 | 22.94 | | | | | Part B R1+R2 | | | | |

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