IV curves (current-voltage characteristics) for four devices: A resistor with large resistance, a resistor with small resistance, a diode, and a battery. An ideal battery would have a constant voltage (a vertical line in the IV curve), but this one has an internal resistance that causes the IV curve to tilt slightly away from vertical. All four plots use the passive sign convention.
Own work Translation, based on File:FourIVcurves.svg by Sbyrnes321
Д.Ильин