## Licensing

Licensed under the CC BY 4.0

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Reference: What Is Faraday’s Law of Induction?

# General Description

The learner moves a magnet around the playing area. As the magnet moves in the proximity of the coils, the light bulb will turn on (and off) with varying amounts of intensity. Voltage meter simultaneously displays an analogue reading.

# Observations

• Brightness of lightbulb is dependent upon speed of the magnet passing near the coils, and the proximity of the field lines.
• The brightness of the bulb (and subsequent falloff) is another representation of the voltage meter
• Emerging design challenges:
• How to describe the proximity of the magnet to the coil?
• This would be easier if we can describe the proximity in terms of the magnetic field, but what should the text descriptions be if the "field lines" option is disabled?
• How do you give a keyboard or switch user the ability to control speed of movement of the magnet? Is speed relevant? Does it affect the lightbulb and voltage meter state?
• Multiple things could happen when you move the magnet:
• Magnet position changed
• Magnet position stayed the same
• Light bulb state changes
• Voltage meter state changes
• Lightbulb and voltage states are temporary and diminishes quickly: this will need to be communicated to an AT.
• Coil presents as an object during interaction. Magnet cannot be placed on top of the coil and can only enter and exit the coil through the openings on either end.

# Relevant Terms, Items and Actions:

Voltage meter or Galvanometer (sensitive current meter): shows induced current

Field lines: lines of magnetic flux. Enter south, exit north

Flux: magnetic field often depicted as lines of magnetic flux. In reality a magnetic field is smooth and continuous.

Wire loops or coils

Circuit

Light bulb: electrical energy in the form of light and heat resistance: “...would feel resistance to the motion of the magnet. In order to move the magnet, we have to do work that is equivalent to the energy being used by the light bulb.”

## Questions

• Are there details which are not important or relevant?
• i.e. the positive and negative terminals on the volt meter? The position of the wires attached to the lightbulb?
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