Read Circuits: Follow the Complete Current Path
A lamp glows only when there is a complete conducting path through it. Work from the cell terminal around the circuit; do not guess from where a component is drawn.
Electricity questions depend on identifying charge, a conducting path and the condition that controls current or magnetic effect.
A bulb needs one unbroken conducting loop
Closed conducting loop → bulb can glow
Trace from one cell terminal, through the bulb, and back to the other terminal. A low-resistance bypass is a short circuit.
Classify the path
A conductor allows current to pass; an insulator does not. A bulb lights only if both of its terminals connect through conducting material to different battery terminals.
Spot a short circuit
A short circuit is a very low-resistance path that bypasses the intended load. Current takes the easy path, so the load may not work and the wire can overheat.
Interpret a conducting liquid
If a bulb lights in a liquid circuit, the liquid conducts because it contains mobile charged particles. It conducts electricity; it is not itself the source of electrical energy.
OlympIQ exam lens
- ✓Trace a closed loop through the lamp.
- ✓Mark conductors and insulators separately.
- ✓Ask whether a wire bypasses the load.
Pure water is a poor conductor, while ordinary water may conduct because dissolved salts supply ions.
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