in the bellow diagram the red box could represent a wire, a bulb, a resistor or a diode.
By changing the resistance of the variable resistor the graphs are reproduced.
![V-I graphs 1](https://www.tutormyself.com/wp-content/uploads/V-I-graphs-1.png)
![VI graphs 2](https://www.tutormyself.com/wp-content/uploads/VI-graphs-2.png)
in the bellow diagram the red box could represent a wire, a bulb, a resistor or a diode.
By changing the resistance of the variable resistor the graphs are reproduced.