Survey

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Survey

Document related concepts

no text concepts found

Transcript

Ohm’s Law Name: ………………………………………… Class: ……………….. Date: ……………….. OBJECTIVES Determine the mathematical relationship between current, potential difference, and resistance in a simple circuit. Figure 1 HYPOTHESIS MATERIALS Ammeter Adjustable 12 volt DC power supply Connected wires Two resistors (about 10 and 50 ) PROCEDURE 1. With the power supply turned off, connect the power supply, 10 resistor, wires and ammeter as shown in Figure 1. Take care that the positive lead from the power supply and the red terminal from the ammeter are connected as shown in Figure 1. Note: Attach the red connectors electrically closer to the positive side of the power supply. 2. Turn on the power supply. Slowly increase the potential to 2 V, 4 V and so on. Record the readings of ammeter and power supply in table 1. 3. Calculate the resistance for each time by using ohms law: V = IR 4. Plot a single graph of potential vs. current. a. Plot Voltage on the y-axis (the vertical axis) b. Plot Current on the x-axis (the horizontal axis) 5. Calculate the slope of the graph. DATA TABLES RESISTOR 1 Voltage Current Resistance (V) (A) (Ω) RESISTOR 2 2 4 6 8 10 12 Voltage Current Resistance (V) (A) (Ω) ANALYSIS Answer the following questions 1. What happened to the current as the voltage was increased? If the voltage is doubled what happens to the current? 2. What was the shape of the graph you obtained? What kind of relationship exists between voltage and current? How close is your y-intercept to zero? 3. How do the values of the constants you got in each of the above equations (in the tables) compare to the value of the slope you calculated? 4. Compare the value of the slope to the actual value of the resistance. Calculate the percentage error. 5. Do your resistors follow Ohm’s Law? How can you tell? 6. Write an equation for each resistor in the form Voltage = constant current. (Use a numerical value for the constant.)