Ohm's Law Lab
Objective:
To verify Ohm’s Law, that V=IR, by manipulating voltage and then plotting it against the
current. Current is a dependent variable while Voltage is independent. Resistance stays the same.
Procedure:
Connect a resistor to a DC generator and then turn it on. Note the voltage and current. Change
the voltage and write down the corresponding current. Be careful not to input more voltage than
the resistor can handle. Repeat this process ten times.
Raw Data:
Volts
Current
7
0.229
8
0.263
9
0.295
10
0.328
11
0.361
12
0.394
13
0.427
14
0.46
15
0.493
16
0.526
Data Analysis:
V=IR
I/V = 0.33, slope of trendline
V/I = R, reciprocal of I/V
R = 1/0.033
R = 30.03
Questions:
1. The maximum voltage allowed was 17 V, and if we exceeded this it would damage the
resistor.
2. Current and Voltage appear to have a linear relationship.
3. High values of V might break the resistor and in turn, the linear relationship. As long as
the voltage does not exceed what the resistor can handle then the relationship should
remain constant.
4. The calculated resistance was 30.03 Ohms, which is almost a perfect match to what the
resistor was listed as - 30 Ohms.
Discussion
Overall I learned that some scientific formulas are dependent on certain outside factors (in this
case the resistor) and trust that the measurements of these devices are accurate. I also learned that
the formula breaks down if you exceed the value allowed for by the resistor. Our measurements
were very accurate, and the final value we found was almost identical to the actual value.
However, not rounding our voltage values could have made it better, despite how little we
actually rounded. This was a possible source of error. Also, since the resistor has been used
before, it could have lost some of its potency. To improve our results, using a brand new resistor
would be our best option. Also, not rounding any digits.