P3 - Electric Circuits Flashcards
How does a transformer work?
Transformers alternate magnetic field along iron core, induces changing voltage across other coil.
What is the process inside an electric generator?
Magnet moves in wired coil, voltage induced. In moving-coil microphone, diaphragm vibrated, attached to coil. Induced voltage drives current, generates opposing field. Dynamo, split-ring commutator, reverses current
What are magnets / magnetic fields, and how are they used?
Induced, within field, magnetises. Permanent, always magnetised. Field lines, north → south. Compass, towards Earth pole. Current, anti-clockwise magnetic field. Coiling, strengthens. Speakers, current field interacts with permanent field, pushes cone.
How do series and parallel circuits work, and how can you investigate bulb brightness in either type?
Series, current same all-around, series resistors increase resistance. Parallel, voltage same all-around, series resistors decrease net-resistance, total current = sum of branches’ current. Brightness: series (1 ammeter, voltmeter per bulb), parallel (voltmeter + ammeter per bulb).
What is current, charge, resistance and voltage?
- Current, flow of charge, voltage source & closed circuit required.
- Charge (C) = current (A) x time (s).
- Voltage = current (A) x resistance (Ω).
- Resistance, variable / fixed, slows current.
What is static electricity and what is an electric field?
Two insulators rubbed, becomes charged. Electrons transferred, like repels, opposite attracts. One positively-charged, other negatively. Electric field, charges experience forces. When another enters, interaction between, force experienced.
