Physics ohm's law lab report

Lab Assignment: Ohm’s Law Laboratory: Introduction This lab will verify and demonstrate Ohm’s law. In this lab, you will study how current, voltage, and resistance are all related to each other and also determine the unknown resistance. First, design an experiment you could construct that might measure current and resistance. • • • • What materials would you use? What would you measure? What results would you expect? What if the results were different; what would that indicate? Lab Assignment: Ohm’s Law Laboratory: Description Developing a Hypothesis: According to Ohm’s law, the current, resistance, and voltage are all related to each other in a circuit. In this experiment, you will find the various values of current for the corresponding values of potential differences. The values of potential differences can be altered or changed by connecting different numbers of cells in a series. • • Create hypotheses of what you think the results of this experiment will be. When potential difference increases, the current also increases at constant temperature. This is called Ohm’s law. How will changing the resistance change the current for the given value of potential difference? Defend your hypotheses with your knowledge of current and resistors. Your answers will be part of your lab write-up that you submit to your teacher. Objectives: 1. Verify Ohm’s law, . 2. Determine the value of unknown resistance. Lab Assignment: Ohm’s Law Laboratory: Procedure Read the entire lab procedure and plan the steps you will take. 1. You will find the virtual lab on the next page. It may be helpful to download the Ohms Law Lab Report (also found within the virtual lab) before starting the virtual lab simulation. 2. Prepare data tables. 1. Prepare a data table for experiment –I using your spreadsheet program. Label the 3 columns as number of cells connected in series, voltmeter reading (V), and Ammeter reading (A). You will need enough rows for six trials. Prepare a data table for experiment –II, III and IV using your spreadsheet program. Label the 4 columns as number of cells connected in series, voltmeter reading (V), ammeter reading (A) and resistance(R). You will need enough rows for six trials. 3. The experimental setup consists of 10 dry cells, each connected to a 1.5 V source, four carbon resistors, a voltmeter and an ammeter. You can choose a maximum of 10 cells to verify Ohm’s law. An ammeter should be connected in series and voltmeter should be connected in parallel across the cells. Play in the lab a little while to become familiar with how it works. 4. First connect the voltmeter across the cells and record the voltmeter reading. Then connect the positive terminal of the ammeter to the positive pole of the cell and its negative terminal to the resistor. The free end of the resistor should be connected to the negative terminal of the cell as shown in the demo. Once the circuit is closed, record the ammeter reading. 5. Keep the resistance constant; connect as explained in step 4 and note the voltmeter reading and ammeter reading. 6. You can repeat Step 5 to a maximum of six different voltages. Record all data in your table -1 of the experiment-I. 7. Now plot a graph V vs. I. 8. Use any one of the resistors X, Y and Z and make connections to find the different values of the voltages.Now, repeat the same method to find the value of the voltage. 9. For finding the corresponding current, calculate ratio V/I to determine the unknown resistance. Ohm’s Law Laboratory Please Note: The instructions on the previous screen indicated that you should play in the lab a little while to become familiar with how it works.