Final answer:
The two ways to establish the density slope that drives the current are by varying the material and by varying the applied electrical field.
Step-by-step explanation:
The two ways the density slope that drives the current can be established are:
- By varying the material - The number of free charges per unit volume, or number density of free charges, depends on the material. Different materials have different values of density, which affects the slope of the current.
- By varying the applied electrical field - The current density is proportional to the applied electrical field. By changing the strength of the electrical field, the slope of the current can be altered.