The following animation illustrates the principle of electromagnetic induction. A conductor is moved through a magnetic field, with the induced voltage displayed in real time.
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Description of the Animation
Move the gray conductor horizontally through the magnetic field of the horseshoe magnet. The current direction is indicated by a red symbol: A dot means “current flowing out of the plane”, a cross means “current flowing into the plane”.
The induced voltage is calculated according to the law of induction:
\[ U = B \cdot l \cdot v \]
- B: Magnetic flux density (strength of the magnetic field) in Tesla (T)
- l: Length of the conductor in the magnetic field in meters (m)
- v: Velocity of the conductor in meters per second (m/s)
The voltage is displayed in the real-time diagram on the right. Faster movements produce higher voltage peaks, while the direction of movement determines the sign of the voltage.
Interactive Controls
Two parameters can be adjusted in the parameter table:
- Length of the conductor (1-10): Directly affects the induced voltage – a longer conductor cuts through more field lines
- Magnetic field strength (0.5-1): Simulates magnets of different strengths
Physical Background
Electromagnetic induction was discovered by Michael Faraday in 1831. The principle states: When a conductor passes through a magnetic field (or when the magnetic field around a conductor changes), a voltage is induced. The direction of the induced voltage follows Lenz’s law – it opposes the cause of its creation.
Practical Applications
- Generators: Convert mechanical energy into electrical energy
- Transformers: Change voltage levels through alternating magnetic fields
- Induction cooktops: Generate heat through induced eddy currents
- Eddy current brakes: Utilize the braking effect of induced currents