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Voltage, Current, Resistance

Modified 5 days ago by Dev Ramesh

Student version

Requires:

Hardware -

  • LED

  • Various Resistor

  • 9V battery (1/student) (not portable battery of drone)

  • 9V Battery clips

  • Alligator clip leads (4/student)

  • Wire

  • Multimeter (1/student)

Previous lesson - Simple Circuits

Knowledge -

Understanding of the relation of:

  • charge

  • voltage

  • current

  • resistance defined by Ohm’s law

  • causes and effects of short circuit

  • difference between AC and DC

Skills - The ability to build and measure simple circuits using a multimeter

Voltage, Current, and Resistance

Modified 2020-09-05 by Peyton Strong

STANDARDS: Next Generation Science Standards (NGSS) and International Society for Technology in Education (ISTE)

Modified 2020-08-19 by jakerad007

NGSS HS-PS3-1.: Create a computational model to calculate the change in the energy of one component in a system when the change in energy of the other component(s) and energy flows in and out of the system are known.

This is a helpful video that shows Ohm’s Law through a similar experiment done here.

Assessments and Evidence of Understanding

Modified 2020-08-19 by jakerad007

By the end of this lesson, students should have built a circuit and records voltage, current, and resistance, and they have shown that Ohm’s law holds for multiple circuits.

AGENDA (Brief Summary of Activities)

Modified 2020-08-19 by jakerad007

5 min: Intro to Multimeter

40 min: Circuit Activity

5 min: Clean up

Differentiation (strategies for grouping, ELL, and inclusion)

Modified 2020-06-30 by jakerad007

Activity recommended to be done in pairs. Teachers should pair students to support each other’s needs.

Advanced preparation/Materials/Set Up (Including Misconceptions)

Modified 2020-09-05 by Peyton Strong

Teacher Materials

Presentation device for explaination of topics

Classroom Set Up

Might be helpful to have supplies already divided up for students prior to the beginning of class.

SCRIPT OF TEACHING AND LEARNING ACTIVITIES

Modified 2020-04-16 by Garrett Warren

Introducing The Lesson

Modified 2020-09-05 by Peyton Strong

Hook:

  • Put students into pairs. Give each pair a multimeter and a battery and give them a couple minutes to answer these two questions:

What do you know about this device?

What questions do you have?

Let them play around with it. Then, let them share out answers as a class.

Main Lesson

Modified 2020-09-05 by Peyton Strong

  1. Build and measure first circuit: Give the students materials to build a circuit similar to last class’s except without the LED. Show them how to measure voltage, resitance, and current with the multimeter.

  2. Explaination of Ohm’s Law: Ohm’s law states that the current through a conductor between two points is directly proportional to the voltage across the two points. Show how voltage, resistance, and current relate mathmatically using Ohm’s law. (A graphic may be helpful, similar to this one). Explain how “short circuit” is a low resistance, unintended, alternate path through the circuit, and how that could damage components in the circuit, power source, start fire, etc…

  3. Build and measure second circuit: Make the same circuit except for a different resistor, and ask students to prove Ohm’s law using the multimeter.

  4. Build and measure circuit with LED: Make the same circuit except add an LED, and ask students to prove Ohm’s law. (It won’t.)

  5. Explaination of why LED doesn’t observe Ohm’s law

  6. Explaination of AC and DC: Explain the difference between AC and DC. Measures AC from a wall outlet using a multimeter.

If time: Brief overview (no math) of other passives (e.g. capacitors resist change in voltage, inductors resist changes in current), actives (controlling flow, diodes as one-way valves, transistors as switches, mention that you can do logic/calculations by combining them), and “integrating circuits” into ICs, assembling those into computers, robots, etc.

Ending The Lesson

Modified 2020-09-05 by Peyton Strong

Clean Up!

Here’s a vocab worksheet for in class or for homework.

Useful Resources and References

  1. Ohm’s Law Explanation

  2. How to Analyze Resistive Circuits Using Ohm’s Law

  3. Electical Circuits and Water Pipes Analogy

  4. Glossary