Ohm's Law Lab
Laboratory Experiment
Introduction:
Ohm's law states that at constant temperatures the current (I) going through a load (R) is proportional to
the potential difference or Voltage (V) across it.
This law can be summarized as a simple but very important equation:
V= I x R
Where:
V is the voltage measured in volts,
I is the current measured in amperes and
R is the resistance measured in ohms.
Purpose: To verify Ohm's Law using experimental procedures.
Materials:

3 resistors of different known values

3 batteries with holders

Connecting wires

Switch

Ammeter

Voltmeter
Procedure:

Connect the circuit below using the first resistor
2. Have your teacher verify your circuit before you turn it on
3. Turn on the circuit and record the value of voltage and current as read by the voltmeter and ammeter respectively in the observation table below.
4. Add a second battery in series with the first and repeat step #3
5. Add a third battery in series with the first and second and repeat step #3
6. Replace the first resistor with the second and repeat steps #3 to #5
7. Replace the second resistor with the third and repeat steps #3 to #5
8. Plot a graph of voltage vs. current for each resistor on the same graph paper
9. Calculate the slope of each line (you should have three lines  one for each resistor)
Observations Table:
Resistor 
[V] Measured Voltage (Volts) 
[I] Measured Current (Amps) 
[R] Calculated Resistance (OHMS) 
1  
2  
3  
Analysis:
1. Write a statement to summarize your observations about the behaviour of voltage and current in an ideal resistor.
2. Write a generalized conclusion
3. Complete the following charts
a) units
Given 
Rewrite these quantities using Equivalent Unit 
14,000 V 
KV 
0.007 MB 
B 
1.7 GHz 
Hz 
370,000 Ω 
MΩ 
0.007 A 
mA 
3.30 kV 
V 
5000 mA 
A 
27 kΩ 
Ω 
b) Using Ohm's Law
Voltage (V) 
Current (I) 
Resistance (R) 
1000 V 
25 mA 
? 
0.01 V 

45 MΩ 
? 
4.0 A 
37 KΩ 
67 V 

Green, blue, violet 
? 
750 mA 
10Ω 
300 V 
1 kA 
? 
? 
300 mA 
Brown, black, red 
450 MV 
1000 mA 
? 