Question

Can you keep the current constant and vary the resistance?

Answer 1

Ohm's law is an equation on three variables: (R=VIR=VI). This means that for given values of two of the variables, you can solve for the third. Or if you set one variable and vary a second, you can see the change in the third.

For example:

Constant resistance, varying the voltage, see the current vary. This is the case where you have a variable voltage source into a fixed resistor. The current through the resistor will vary proportionally to the voltage.Constant resistance, varying the current, see the voltage vary. This is the case where you have a variable current source into a fixed resistor. The voltage across the resistor will vary proportionally to the current.Constant voltage, varying the resistance, see see the current vary. This is the case where you have a constant voltage source connected to a potentiometer (between the wiper and one end). As you vary the resistance, the current will change as the inverse.