The component you’re asking about is the resistor in a circuit, or more generally any component whose resistance increases as the current through it increases. This behavior is characteristic of a non-ohmic device called a positive temperature coefficient (PTC) element, where higher current causes heating, which raises resistance. Key points:
- In many practical cases, heating of a conductor or device causes its resistance to rise with increasing current, especially for resistive elements like lamps or filaments. This is a common example of a component whose effective resistance increases as current (and temperature) rises.
- A classic ideal resistor follows Ohm’s law with constant resistance, so its resistance does not change with current. Real-world components often deviate due to temperature, material properties, or device structure.
- If a component’s resistance changes primarily because charge has flowed through it in a way that alters its internal state (not just temperature), memristive or certain nonlinear devices may exhibit similar behavior, though that’s a more specialized case.
If you’re studying a specific context (e.g., a light bulb filament, a PTC thermistor, or a diode under certain bias conditions), I can tailor the explanation to that case. Would you like a concise explanation for:
- a hot filament lamp (resistance rises with temperature as it heats up under higher current), or
- a PTC thermistor (designed to increase resistance with current/temperature), or
- a general discussion of non-ohmic elements?