PhysicsChapter 8: Electric Circuits
Parallel Circuits
Introduction
A parallel circuit contains two or more conducting branches connected between the same pair of points. Charge can therefore travel through different paths.
Definition
Potential Difference
The potential difference across each parallel branch is the same: **V = V₁ = V₂ = V₃**
Current
At a junction, current divides among the branches. The total current is: **Iₜ = I₁ + I₂ + I₃** The currents recombine when the branches join again.
Resistance
For resistors in parallel: **1Rₜ = 1R₁ + 1R₂ + 1R₃ + ... The equivalent resistance of a parallel combination is less than the smallest individual branch resistance**.
Example
Two resistors, 6 Ω and 3 Ω, are in parallel. `1Rₜ = 16 + 13` `1Rₜ = 16 + 26 = 36` `1Rₜ = 12` **Rₜ = 2 Ω**
Why Parallel Connections Are Useful
Different branches can operate independently. If one branch opens, other complete branches may continue operating. This is one reason household appliances are connected in parallel rather than as one long series chain.
Exam preparation
Exam Focus
Quick revision
Revision Zone
Review the key facts, formulas and checks before you move on.Parallel Circuits
Sticky Notes · Quick Revision
PARALLEL
- Multiple paths
VOLTAGE
- Same
CURRENT
- Splits
Rₜ
- Less than smallest branch R
60-second revision
- Parallel → multiple paths.
- Voltage → same.
- Current → divides.
- Total current → branch currents add.
- Equivalent R → decreases.
Did you understand this topic?
Your answer is saved with your learning record. It does not mark the topic as mastered.