AP Physics C: Electricity & Magnetism delves into the principles of electricity and magnetism, exploring concepts such as electric fields, magnetic fields, and circuits.
Changing magnetic fields can induce electric currents in conductors—a phenomenon known as electromagnetic induction.
Faraday’s Law quantifies induction: \[ \mathcal{E} = -\frac{d\Phi_B}{dt} \] where \( \mathcal{E} \) is the induced emf (voltage) and \( \Phi_B \) is the magnetic flux.
The negative sign shows that the induced current opposes the change in magnetic flux (Lenz’s Law).
Induction is the principle behind generators, transformers, and wireless charging.
Spinning a coil in a magnetic field generates electricity in a power plant.
Moving a magnet through a loop lights a small bulb in hand-crank flashlights.
Changing magnetic fields create electric currents, enabling modern power generation.