Labs / Physics
Faraday Induction
Grab the bar magnet and push it in and out of the coil. A moving magnet changes the magnetic flux threading the loops, and Faraday's law turns that change into an induced current — watch the galvanometer swing and the coil glow. The faster you move, and the more turns you add, the bigger the current.
Φ 0.0 mWb|v| 0 cm/sEMF 0 mVI 0.0 mA 0
What to try
- Hold the magnet perfectly still inside the coil. Why does the galvanometer read zero even though the magnet is right there?
- Move the magnet in slowly, then whip it in fast. What is it about the motion — not the magnet — that sets the size of the EMF?
- Push the magnet in versus pulling it out. Why does the induced current reverse direction?
- Flip the poles and repeat a push. How does swapping N and S change what the galvanometer does?
- Crank the coil turns from 1 to 40 at the same speed. Does doubling the turns really double the induced EMF?