Study Notes
In series circuits, the current is the same throughout, while the total resistance is the sum of individual resistances. In parallel circuits, the current from the source is divided among branches, and the total resistance is less than any individual resistor.
- Series Circuit — A circuit where components are connected end-to-end, so the same current flows through each component. Example: Christmas lights connected in a single loop.
- Parallel Circuit — A circuit where components are connected across common points, allowing multiple paths for the current. Example: Household wiring where each outlet operates independently.
- Current Conservation — In a parallel circuit, the total current entering a junction equals the total current leaving. Example: Water flowing into and out of a junction in a pipe system.
Exam Tips
Key Definitions to Remember
- Series Circuit: Current is the same throughout; total resistance is the sum of resistances.
- Parallel Circuit: Current is divided among branches; total resistance is less than individual resistors.
Common Confusions
- Current is not the same in all branches of a parallel circuit.
- Total resistance in parallel is not simply the sum of resistances.
Typical Exam Questions
- What happens to the total resistance when more resistors are added in series? It increases.
- How does the current behave at a junction in a parallel circuit? It splits and recombines.
- Why are household circuits wired in parallel? To allow independent operation of devices.
What Examiners Usually Test
- Understanding of current and resistance in series vs. parallel circuits.
- Ability to calculate total resistance in both types of circuits.