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Parallel Circuits Overview

Sep 11, 2025

Overview

This lecture explains the properties of parallel circuits, focusing on how they distribute potential difference, current, and resistance among their components.

What are Parallel Circuits?

  • Parallel circuits have more than one loop, with each loop often containing a single component.
  • In parallel circuits, if one component fails, the rest of the circuit continues to work.

Distribution of Potential Difference

  • Each component in a parallel circuit receives the full source potential difference (voltage).
  • For example, with a 12V battery, every component in parallel gets 12V across it.

Distribution of Current

  • The total current from the source splits across the different loops in the circuit.
  • The sum of the currents in all loops equals the total current of the circuit.
  • Loops with lower resistance carry more current, while loops with higher resistance carry less.

Resistance in Parallel Circuits

  • Adding more components in parallel decreases the total (overall) resistance of the circuit.
  • More paths for current make it easier for electricity to flow, reducing total resistance even if new resistors have high resistance.

Key Terms & Definitions

  • Parallel Circuit — A circuit with more than one loop, where each component is on its own branch.
  • Potential Difference (Voltage) — The energy per unit charge supplied by the source, measured across each component.
  • Current — The flow of electric charge, splits between branches in parallel circuits.
  • Resistance — A measure of how much a component opposes the flow of current; in parallel, total resistance decreases as more branches are added.

Action Items / Next Steps

  • Review the differences between series and parallel circuits, especially if unclear on series circuits.