GED Science TestPhysical ScienceMedium
A technician is setting up an experiment to demonstrate the generation of electricity through mechanical motion. They connect a coil of wire to a galvanometer and then rapidly move a permanent magnet back and forth inside the coil. What fundamental principle is this experiment demonstrating?
- ACoulomb's Law
- BElectromagnetic Induction
- CPhotoelectric Effect
- DOhm's Law
Show answer & explanationAnswer & explanation
Correct answer: B. Electromagnetic Induction
Moving a magnet near a coil of wire induces an electric current, which is the core principle of electromagnetic induction. This is how generators produce electricity.
Why the other options are wrong
- A. Coulomb's Law describes the electrostatic force between charged particles.
- C. The photoelectric effect describes the emission of electrons when light shines on a material.
- D. Ohm's Law describes the relationship between voltage, current, and resistance in a circuit.
Electromagnetic Induction
The process by which a changing magnetic field induces an electromotive force (voltage) and thus an electric current in a conductor.
- Discovered by Michael Faraday.
- Basis for electric generators and transformers.
- Requires relative motion between a conductor and a magnetic field.
Memory trick: Motion makes current flow, like a magnet's dance.