Subject 13 · Circuits

Circuits

Start from the circuit language, define current, voltage, and resistance precisely, then combine components and cost the energy they transfer. Every subsection includes a responsive interactive model.

CHARGEIENERGY

the circuit languageCircuit Symbols & Diagrams

Read and draw circuits with standard symbols, and place meters correctly.

→02

I = ΔQ/ΔtElectric Current & Charge

Define current as the rate of charge flow and follow the conventional direction.

→03

V = W/QVoltage & Potential Difference

Measure the energy carried per coulomb between two points of a circuit.

→04

R = V/IResistance & Ohm's Law

Define resistance, read I–V graphs, and state when Ohm's law applies.

→05

R = ρL/AResistivity

Separate the material property from the wire's length and cross-section.

→06

add R or add 1/RSeries & Parallel Circuits

Combine resistors and predict how current and voltage are shared.

→07

P = VI = I²RElectric Power

Rate energy transfer with P = VI and cost it over time.

→08

I = dQ/dtCurrent Calculus

Read current as a gradient and recover charge and energy as areas under a graph.

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Free game · I = V/R and P = I²RCircuit Rush

Play free, no account needed: wire a limited stock of resistors into a series bank, a parallel bank, or a shunt across the lamp until the meters hit the ordered current or wattage — without blowing the lamp or tripping the fuse. Six timed benches.

→Slides

Members · classroom mode, full screenPresent this chapter

Full-screen slides for the classroom, built from the lessons themselves: pick a lesson, then reveal its idea, formulae, quick check, and worked examples one step at a time.

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