Brainlag PlusBranches: the same p.d. across each, currents that add at a junction, and a total resistance smaller than any branch.
The three parallel rules
In a parallel circuit each component has its own branch, connected straight across the supply.
- Potential difference: each branch has the full supply p.d.
- Current: the branch currents add up to the total: A = A₁ + A₂.
- Resistance: the total is less than the smallest branch resistance.
- 6.0 V supply, R₁ = 3 Ω, R₂ = 6 Ω in parallel
- Each branch has 6.0 V across it
- A₁: I = 6.0 ÷ 3 = 2.0 A
- A₂: I = 6.0 ÷ 6 = 1.0 A
- A: 2.0 + 1.0 = 3.0 A
The rest of this lesson and its 7 practice questions are in Plus.
Screen 1 of 4, free to read.
- 7 exam-style questions, marked as you go, each with a worked solution
- The Ohm's Law and Circuits Calculator</b> and the <b>Series and parallel circuits simulation beside every question
- Anything you get wrong is saved to your flashcards