Course: Engineering Design I

### Electrical Systems

Standards

In this task students will use a simulation to demonstrate how to measure voltage, current and resistance.

Standard 22: Calculate voltage, current, and/or resistance in a DC circuit using Ohm’s la (V=IR). Explain how Ohm’s Law relates voltage, current, and resistance, citing technical examples for illustration. For example, if voltage remains constant and resistance decreases, the current will increase. Given a physical circuit, demonstrate how to measure each using a digital multimeter. Where unexpected behavior is observed, cite specific evidence to explain the observations. Prepare an informative report comparing calculated values with measured values and include an explanation of any sources of error.

Content Understandings

Extending Understandings

Upon successful completion of these tasks students will demonstrate the ability to:

1. Calculate current using the Ohm’s law simulator.
2. Explain how Ohm’s Law relates voltage, current, and resistance.

To move students towards deeper understanding, they should be given opportunities to:

• Explain the correlation between resistance, current and voltage.
• Explain Ohm’s law using a real-world scenario.

Support Strategies

If students are struggling to access this task, additional supports and strategies could be employed as students are engaging with the task.

 Key Terms Sentence Frames Scaffolded Questions Voltage   Current   Resistance   Ohm’s Law To study electric currents in circuits, we need to understand how to measure currents and _____. The electric field set up in the conductor is also proportional to the _____. ___ has SI units of volts per ampere, called ohms. ___ is an empirical relationship valid only for certain materials. What happens if voltage remains constant and resistance decreases? Why is current significant to Ohm’s law? If the resistance of an electrical circuit is increased, what will happen to the current assuming the voltage remains the same? What does Ohm’s law describe?

Instructional Resources

Ohm’s Law Simulation

• Simulation
• This simulation is not compatible with Internet Explorer.

This simulation is attributed by:

PhET Interactive Simulations

## Student Resources

### Ohm’s Law Simulation Practice

Directions: Students will use the Ohm’s Law simulator to solve for current given voltage and resistance.

 Voltage Current Resistance 4.5V 500 Ohms 9.0V 500 Ohms 0.1V 500 Ohms 4.5V 30 Ohms 9.0V 30 Ohms 0.1V 30 Ohms 4.5V 900 Ohms 9.0V 900 Ohms 0.1V 900 Ohms

 Explain how Ohm’s law relates voltage, current and resistance citing technical examples. (3-5 sentences)