I-V characteristics sim
Sliding the rheostat's contact changes how much resistance wire the current passes through, so it changes the current, and the p.d.
I-V characteristics · covers the GCSE, IGCSE, O-Level topic
What the sim shows
Sliding the rheostat's contact changes how much resistance wire the current passes through, so it changes the current, and the p.d. across the component. Each reading of the voltmeter (V) and ammeter (I) is a point on the I-V graph; turning the battery round gives negative readings. The resistor's graph is a straight line through the origin: I ∝ V, its resistance V/I stays 10 Ω (an ohmic conductor, at steady temperature). The filament lamp's line curves over: as the current heats the filament, its resistance rises (from about 9 Ω to 20 Ω here). The diode conducts only one way, and only once the p.d. is above about 0.6 V; backwards almost no current flows. A 100 Ω resistor protects the diode. The meters are taken as ideal.
- The rheostat's sliding contact
- Right: the I-V graph
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