Electromagnetism & Induction Task

Part 1: Engage (Anchoring Phenomenon)

Imagine you are lost in the woods with only a compass. Suddenly, lightning strikes a nearby tree. You notice that the compass needle briefly spins wildly before settling back to point North.

• Why did the compass needle react to the lightning strike even though lightning is electricity, not a magnet?
• Can we create a magnet using only electricity?
• Conversely, can we generate electricity using only a magnet?

Student Questions:

1. Record two “need to know” questions you have about the relationship between electricity and magnetism.

Part 2: Explore (Simulation Investigation)

In this section, you will use the “Electromagnetism & Induction” simulation to investigate the relationship between electric currents and magnetic fields.

Part A: Electromagnetism (Tab 1)

1. Setup: Ensure you are on the “Electromagnet Controls” tab. You should see a battery, a coil of wire, and a compass.
2. Investigation:
   • Set the Battery Voltage to 0V and the Number of Loops to 3.
   • Drag the compass around the coil. Record the Compass Field (B) in milliTeslas (mT).
   • Increase the Battery Voltage to 5V, then 10V. Drag the compass around and observe the Compass Field (B) and the direction of the compass needle.
   • Change the Number of Loops while keeping the voltage at 10V. Observe the changes in the magnetic field.
   • Reverse the Battery Voltage to negative values (e.g., -10V). What happens to the compass needle?

Data Table A: Electromagnetism Observations | Voltage (V) | Number of Loops | Compass Position | Compass Field (B) (mT) | Needle Direction | | :— | :— | :— | :— | :— | | 0 | 3 | Near coil | | | | 5 | 3 | Near coil | | | | 10 | 3 | Near coil | | | | 10 | 10 | Near coil | | | | -10 | 10 | Near coil | | |

Part B: Induction (Tab 2)

1. Setup: Switch to the “Induction Controls” tab. You should see a coil of wire connected to an ammeter (which measures current) and a permanent magnet.
2. Investigation:
   • Set the Number of Loops to 3.
   • Slowly drag the permanent magnet near and through the coil. Observe the Induced Current (I) in Amperes (A) on the ammeter.
   • Drag the magnet quickly near and through the coil. Note the difference in the induced current.
   • Stop moving the magnet while it is inside the coil. What is the induced current?
   • Change the Number of Loops to 10 and repeat the fast movement. Note the induced current.

Data Table B: Induction Observations | Magnet Movement | Number of Loops | Max Induced Current (A) | | :— | :— | :— | | Stationary (outside) | 3 | | | Moving Slowly | 3 | | | Moving Quickly | 3 | | | Stationary (inside) | 3 | | | Moving Quickly | 10 | |

Part 3: Explain (Sensemaking)

Use your observations from Part 2 to answer the following questions.

1. Electromagnetism: Based on Data Table A, what evidence supports the claim that an electric current produces a magnetic field? How do the voltage (current) and the number of loops affect the strength of the magnetic field?
2. Directionality: What happens to the magnetic field when the direction of the electric current is reversed (by using a negative voltage)? Cite specific evidence from your observations.
3. Induction: Based on Data Table B, what evidence supports the claim that a changing magnetic field produces an electric current? Why is there no current when the magnet is stationary inside the coil?
4. Variables: How does the speed of the magnet and the number of loops affect the amount of induced current?

Part 4: Elaborate/Evaluate (Argumentation)

Prompt: Write a scientific argument supporting the following claim: “Electricity and magnetism are two aspects of the same phenomenon, where one can be used to generate the other.”

Your argument must include:

• Claim: State whether you agree or disagree with the prompt.
• Evidence: Provide specific data points from both Part A and Part B of your investigation (e.g., specific voltage, magnetic field strength, magnet movement, and induced current values).
• Reasoning: Explain why your evidence supports the claim, specifically mentioning that an electric current creates a magnetic field and that a changing magnetic field induces an electric current.

Teacher Notes

Alignment to NGSS:

• Performance Expectation: HS-PS2-5: Plan and conduct an investigation to provide evidence that an electric current can produce a magnetic field and that a changing magnetic field can produce an electric current.
• Science and Engineering Practices (SEPs): Planning and Carrying Out Investigations
• Disciplinary Core Ideas (DCIs): PS2.B: Types of Interactions, PS3.A: Definitions of Energy
• Crosscutting Concepts (CCCs): Cause and Effect

Evidence Statements:

1. Identifying the phenomenon: Students describe that an electric current produces a magnetic field and that a changing magnetic field produces an electric current. (Demonstrated in Part 3 and Part 4 responses).
2. Identifying the evidence: Students describe the data that will be collected uniquely related to the presence of an electric current/magnetic field, and why these effects are causal. (Demonstrated by completing Data Tables A and B, and answering Part 3).
3. Planning for the investigation: Students use a circuit with a source, coils, compass, and ammeter to measure current and magnetic fields. (Demonstrated by completing Part 2 procedures).