Ohm's law states that V=IR where V is the voltage in volts (V), I is the current in amperes (A), and R is the resistance in ohms (S). In an experiment to verify Ohm's law, the resistance of a circuit is increased from 1.0 $ to 10.0 S2, and the corresponding current is recorded at a constant voltage of
10.0 V. The table below shows the results of the experiment.
R (S2)
• I(A)
1.0
9.8
2.0
5.2
3.0
3.0
4.0
2.3
5.0
2.0
6.0
1.7
7.0
1.5
8.0
1.3
9.0
1.1
10.0
1.0
Identify the dependent and independent variables.
b. Make a graph with the dependent variable on the y-axis and the independent variable on the
d.
Did you get a linear graph? If not, linearize your graph.
For your graph, draw the best fit line. Determine the slope of the line. What does the slope
represent?
e. Can you get the voltage out of your graph? If yes, how? Compute the percent error of your voltage. Use 10.0 V as the accepted value.
Answer (1)
a.Independent variable: Resistance (R)Dependent variable: Current (I)b.Plot R (ohms) on the x-axisPlot I (amperes) on the y-axisc.No, the graph is not linear.To linearize: Graph 1/R vs. Id.Best-fit line from linearized graph gives slope ≈ 10.0 VThe slope represents the voltage (V) in Ohm’s Law: V = IR → I = V × (1/R)e.Yes, you can get the voltage from the slope of the linearized graph.Slope = 10.0 V (from best-fit line)Percent error = |(10.0 - 10.0) / 10.0| × 100 = 0%
