Demonstrate Ohm’s Law using digital multi-meters. Fun hands-on activities are presented that demonstrate Ohm’s Law. Teachers use digital multi-meters to collect data that are plotted to show that voltage and current are related by linear functions for ordinary resistors and by power functions for light bulbs.
Learn about Ohm’s Law. Be able to use a digital multi-meter to collect data. Explore the concepts of voltage and current.
Anticipated Learner Outcomes
As a result of the activities, students should develop an understanding of:
Relationship between Voltage, Current, and Resistance in an electrical circuit
Measurement, plotting data, and graphing
Basic wiring and construction of a digital multi-meter for data collection
The activity consists of using a nominal six-volt battery (made up of four nominal 1.5 volt dry cells connected in series) to:
Drive current through a simple circuit element and measure and record the current through the element and the voltage across the element as the number of cells in the battery is varied from a single cell to four cells.
Plot points on the graph that represent the voltages and currents recorded.
Draw a “best fit” curve through the data points for the element tested.
Repeat the process for two or three different resistor circuit elements.
Compare the curves and make observations about the nature of the curves for each element.