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Get Connected With Ohm's Law

Get Connected With Ohm's Law

Lesson Focus

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.

Download Student Worksheets RTF

Lesson Synopsis

Fun hands-on activities are presented that demonstrate Ohm's Law (E = I x R). 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.

## Age Levels:

10

18

Objectives

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:

- Ohm's Law
- 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

Introduction

What is Ohm's Law?

Ohms Law is a mathematical equation explaining the relationship between Voltage, Current, and Resistance within electrical circuits. It is defined as follows:

**E = I x R**

**E = Voltage**(Voltage is an electric potential difference between two points on a conducting wire. Voltage is measured in volts and comes from various sources such as electric outlets and batteries.)**I = Current**(Current is measured in amps. Current is charged particles which flow from the voltage source through conductive material to a ground.**R = Resistance**(Resistance is the opposition that a material body offers to the passage of an electric current. Resistance is measured in ohms. Examples of items with resistance are light bulbs and coffeemakers.)

## Lesson Activities

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.

Six teacher handouts are provided:

- Ohm's Law Information Sheet
- Step By Step Lesson Plan Guidelines
- Appendix 1: Materials Sourcing Suggestions
- Appendix 2: Continuity Tester Assembly Instructions
- Appendix 3: Alternate Single Cell Battery Holder Photos and Diagrams
- Appendix 4: Optional Insulators and Conductors Activity

Two student handouts are provided for advance review:

- Ohm's Law Information Sheet
- Step By Step Procedures

Resources/Materials

See attached student worksheets and teacher resource documents.

## Alignment to Curriculum Frameworks

Curriculum alignment sheet is included in PDF.

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