Title: Ohm's Law and Circuit Resistance
Build the circuit as shown in the above figure by using the 1 kΩ resistor. Set the DMM to measure DC current and insert it in-line between the source and resistor. Set the source for zero volts. Measure and record the current in the following Table. Note that the theoretical current is 0 and any measured value other than 0 would produce an undefined percent deviation.
| Voltage (volts) | Theoretical (A) | Measured (A) | Deviation (%) |
|-----------------|-----------------|--------------|---------------|
| 2 | | | |
| 4 | | | |
| 6 | | | |
| 8 | | | |
| 10 | | | |
| 12 | | | |
Setting Voltage at 2 volts, determine the theoretical current based on Ohm’s law and record in the Table. Measure the actual current, determine the deviation, and record these in the Table.
Repeat step 2 for the remaining source voltages in the Table.
Using the measured currents from the Tables, create a plot of current versus voltage. Voltage is the vertical axis and current is the horizontal axis. The slope of the line is equivalent to the resistance. Find that slope and compare it with the theoretical resistance value.
Deviation = (Measured - Theoretical) / Theoretical × 100
V = I × R
1. Does Ohm’s Law appear to hold in this exercise?
2. Is there a linear relationship between current and voltage?
3. What is the relationship between the slope of the plot line and the circuit resistance?