
Principle:
Electromagnetic induction, discovered by Michael Faraday in 1831, states that:
"A changing magnetic field induces an electric current in a conductor."
Setup:
1. 44 SWG (0.305 mm diameter) wire from an old clock circuit
2. 500 turns wound on a 5ml syringe (forming a coil)
3. N52 Neodymium magnet
4. LED connected to the coil
Operation:
1. When you move the magnet up and down near the coil, the magnetic field changes.
2. This changing magnetic field induces an electromotive force (EMF) in the coil.
3. The EMF generates a small electric current in the coil.
4. The current flows through the LED, causing it to glow.
Key Factors:
1. Coil turns: 500 turns increase the induced EMF.
2. Magnet strength: N52 Neodymium magnet provides a strong magnetic field.
3. Wire gauge: 44 SWG wire is relatively thin, increasing the coil's resistance.
4. Motion: Moving the magnet creates a changing magnetic field.
Faraday's Law of Induction:
ε = -N(dΦ/dt)
Where:
ε = induced EMF
N = number of coil turns
Φ = magnetic flux
d/dt = rate of change of magnetic flux
Applications:
1. Generators
2. Motors
3. Transformers
4. Induction coils
5. Wireless charging