Secondary
Secondary Physics: From Ohm’s Law to Confident Circuit Reasoning
•By Intuitional Team•1 min read
A practical playbook to avoid the most common series–parallel mistakes and compute power safely.
Core laws
V = IR, P = VI = I²R = V²/R. In series, current is the same; in parallel, voltage is the same.
Reasoning steps
- Mark knowns on the diagram.
- Reduce obvious series/parallel groups.
- Compute equivalent resistance, then total current.
- Back‑substitute to find branch currents and voltages.
Frequent errors
- Adding parallel resistances directly.
- Forgetting that bulbs are non‑ohmic when very hot.
- Mixing up potential difference vs emf.
Train with mixed problems: start with two‑loop circuits, then add internal resistance and power ratings.
Tags
SecondaryPhysicsElectricityOhm's LawCircuits