CT-STEM

Overview

In this lesson, students will start to familiarize themselves further with the concepts of current and resistance by investigating different materials that are good conductors (measured current is high) and poor conductors (measured current is low). While this lesson has "investigating resistivity" in its title, the actual investigation will be much more qualitative in nature. Later on students can investigate resistance in more depth, and come away with an understanding of the different variables that affect resistance. If helpful, you can recall experiences they might have had, such as their parents warning them not to stick metal, like a paperclip, in an electrical socket. They have also seen a short circuit during the simulation activity. (Note: As often as possible, tying together the real life and simulated experiences can only help them make connections between computational thinking and what they're learning in science class.)

Another main goal of this lesson is to teach students how to use a multimeter. Students may be able to sort the materials into good and poor conductors very quickly, but using a multimeter successfully takes some thought and practice. Students should be given explicit directions on how to use the multimeter correctly, and warned that if they handle it improperly, they could break it.

Standards

Next Generation Science Standards

Engineering, Technology, Applications of Science

[HS-ETS1] Engineering Design

Physical Science

[HS-PS3] Energy

NGSS Crosscutting Concept

Systems
Energy

NGSS Practice

Analyzing Data
Constructing Explanations, Designing Solutions
Using Models
Using Mathematics
Conducting Investigations

Computational Thinking in STEM

Data Practices

Analyzing Data
Collecting Data
Visualizing Data

Modeling and Simulation Practices

Assessing Computational Models
Constructing Computational Models

Computational Problem Solving Practices

Computer Programming
Troubleshooting and Debugging

Credits

Unit designed by Melissa Beemsterboer a teacher at Lindblom.

Activities

1. Pre-lesson questions
2. Measuring Current
3. Extension - What are Wires, Really?

Student Directions and Resources

In this lesson you will be investigating which materials make good conductors, and which don't. (Often poor conductors are good insulators.) While you may already have some knowledge of how to sort your materials before you begin, you will need to actually measure the currents they produce with a multimeter. Pay close attention to the directions your teacher gives you on how to use the multimeter. If you use it improperly, it will break.

1. Pre-lesson questions

Brainstorm for a bit about the relationship between current and resistance.

Question 1.1

If you have high resistance, what will happen to the current in the circuit? If you have low resistance, what will happen to the current in the circuit?

A high resistance will produce a high current, a low resistance will produce a low current
A high resistance will produce a high current, a low resistance will produce a high current
A high resistance will produce a low current, a low resistance will produce a high current.
A high resistance will produce a low current, a low resistance will produce a low current.

2. Measuring Current

Watch your teacher to learn how to properly use a multimeter. You need to make sure that your multimeter is properly set up before measuring current in your circuit, so you don't blow your multimeter.

When your teacher has finished the demonstration, set up a circuit with your wires, battery, multimeter, and one of your materials to test.

Once you have set up your circuit, measure the current produced by each material and record your data. When you are finished with your investigation, answer the questions below

Question 2.1

Fill in the data table below with the materials and current values that you received from the lab. To add more data, click the + symbol in the bottom row.

Question 2.2

Which materials made good electrical conductors?

Question 2.3

Which materials made good electrical insulators?

Question 2.4

What type of clothes and shoes might you want to be wearing if you know you are going to be in close proximity to electrical circuits? For instance, what types of clothes would electricians wear?

3. Extension - What are Wires, Really?

Think back to your activity where you made the light bulb light using two wires, a battery and a bulb. Then think about the scenario where you only used one wire and a bulb, and how you were able to try a few orientations that worked.

Question 3.1

Would this circuit work if the wires were slightly longer?

Yes
No

Question 3.2

Would this circuit work if the wires were slightly shorter (but could still reach everything they needed to)?