In this paper, we present a demonstration of Ohm's law on a spreadsheet. Students can perform an experiment of Ohm's law like they perform in laboratories. The only difference is that the apparatus is virtual. The students record readings of current through the circuit and potential difference across a resistor. A graph is drawn between I and V to show the linear relationship between these quantities. There are two parts of the experiment. In the first part, students verify Ohm's law and calculate the resistance of a resistor. In the second part, students find an unknown resistance by finding the slope of the "I-V" graph.