LuduminaEL-06 · EL-U2 · Planned
Parallel circuits
Learning objectives
Use equal branch p.d. and total current; explain reduced total resistance as branches are added.
DfE single-science pp.39–41 / Combined pp.33–34. Evidence checked 30 September–1 October 2026. Skills: WS1.2,1.4; MS3c,3d.
Needs firstEL-05
Explanation
Parallel branches share the same supply p.d. Their currents depend on branch resistance and add at junctions. Adding an extra branch increases total current at fixed supply p.d., so equivalent resistance decreases.
Concepts, equations and units: I_total=sum branch currents; each branch V=V_supply; equivalent R=V/I_total; no reciprocal formula required.
Prediction, demonstration and game exercise
Predict, observe, explain
Compare series and parallel lamps; remove one branch and measure remaining current.
Planned learner game exercise
Build a two-branch lighting system and diagnose a broken branch from meter data.
Independent practice
Calculate branch and total currents then equivalent resistance; explain domestic circuit advantages.
Original practice example · Shared
A 6 Ω and a 3 Ω resistor are in parallel across 6 V. Find branch currents, total current and equivalent R.
Show working and model answer
Working / reasoning
I1 = 6/6 = 1 A; I2 = 6/3 = 2 A; total = 3 A; R_eq = 6/3.
Answer
1 A and 2 A; total 3 A; equivalent 2 Ω.
Exit check and success criteria
Two correct calculations and correct independent-branch explanation.
During practice, compare the prediction with evidence and give an error-specific prompt. The exit item uses a fresh context or fresh values, answered independently.
Misconceptions, practical links and mastery
Check these misconceptions
Parallel branches share current equally regardless of resistance; adding parallel resistance increases total R.
Practical preparation
RP-P3/RP-C15 parallel part; AT6,7.
Virtual preparation and revision only. Required hands-on activities and school records remain separate.
Proposed mastery
0: not yet evidenced. 1: supported. 2: independent exit criteria met. 3: successful changed-context transfer. Advance at 2; revisit with fresh retrieval. These are not GCSE grades.