1. Experiment to Verify Ohm’s Law
Rolla Tyas Amalia
Grade 11
“For a conductor at constant temperature, the current in the conductor is
proportional to the potential difference across it.”
Introduction
Ohm’s law is used in electrical engineering to calculate the relationships between
current, voltage and resistance. The calculations are required to design a safe
circuit. Ohm’s law is apply in our every-day life in electrical things that we use,
such as light bulbs, electric stoves, and others. Ohm’s law was discovered by a
scientist named Georg Simon Ohm. It published in his paper titled The Galvanic
Circuit Investigated Mathematically in 1827. Ohm’s principal discovery was that
the amount of electric current through a metal conductor in a circuit is directly
proportional to the voltage across it, for any given temperature. Ohm expressed
his discovery in the form of a simple equation, describing how voltage, current,
and resistance related to each other: V=IR
Hypothesis
The experiment setup consists of a simple circuit with a variable resistance and
simple power source, which are 3 batteries (1.5 Volt each). The diagram beside
shows the single circuit that we will use for this
experiment:
We could choose a Voltage range and then vary
the value of the resistance over the range. As
expected from Ohm’s law, it will be seen the
voltage range and value of the resistance
chosen will be linear and the value of
resistance will be perpendicular to the current.

2. Experiment
Apparatus:
1. 4 varied value of resistors
2. Power supply
3. Connecting wires
4. Multimeter
Variables:
Independent: Resistance
Dependent: Current
Controlled: Electromotive force
Procedures:
1. Set up the apparatus to be the circuit as shown in diagram of hypothesis.
2. Set the value of electromotive force into 3 V.
3. Put the 12-ohm resistor and see the value of current in the Multimeter.
4. Change the 12-ohm resistor with 82 and 470-ohm resistor variedly and
repeat step 3.
5. Change the value of electromotive force into 6 V.
6. Repeat steps 3 and 4 (use 56-ohm resistor instead of 12-ohm resistor,
because the value of 12-ohm resistor is too small for 6V of electromotive
force).
7. Record the data in this table:
Experiment In Calculation
Current Resistance Voltage V = IR
0.215 A 12 Ohm 3V 2.58 V
0.037 A 82 Ohm 3V 3.03 V
0.007 A 470 Ohm 3V 3.29 V
0.105 A 56 Ohm 6V 5.88 V
0.073 A 82 Ohm 6V 5.98 V
0.013 A 470 Ohm 6V 6.11 V

3. Analysis
From this experiment, we can see that the values of voltages depend on how big
are the values of resistors. The bigger the values of resistors, the bigger the
values of electromotive force will be resulted. This shows that the voltage range
and resistor value is linear to each other, while perpendicular with the value of
current. For more clear details, see the table of the experiment data above.
Conclusion
The value voltage range in a circuit will be linear with the value of resistor
chosen, and perpendicular with the value of current resulted.