So does ohms law say if the resistance is increased the voltage will also increase but not the current? And in non ohmic conductors the current increases with the voltage even though the resistance is also increasing? (meaning it shouldn't but still is, defying the law thereby)
In every electric system through which there is some current flowing, e.g. a conducting metal wire, there is a driving force. This driving force is expressed throug the potential difference established through the wire. This is voltage. So, voltage is a cause, current is effect. If you change voltage lets say, you double the voltage, current will surely increase. If you plot this and your graph is a line, you are dealing with Ohmic resistance. Slope of this linear graph is defined as a resistance and it is constant (if you plot voltage on y and current on x axis). If your graph is not a line but curve, slope of this curve will change and by definition, the resistance. So, resistance itself is dependent and not constant. Definiton of resistance is: voltage drop/change in current. So Ohms law is all about constant resistance. If there is constant resistance, then Ohms law holds.
Ohm's law cannot be applied for non-ohmic resistances ( inductors, capacitors, solid-state devices).
Ohm's law just says that current depends on the voltage of the EMF source and the ohmic resistance of the circuit.
It states that there is a voltage drop, between 2 ends of a resistor.
So does ohms law say if the resistance is increased the voltage will also increase but not the current?
Well that is true (in a strange kind of way) but it would be better to say: if the resistance is increased, it will require an increase in voltage to keep the current the same.
Ohms law relates three variables.
If you change one of those, then the other two have to change in a coordinated way: if R goes up, the V has to go up, or I has to go down, or some combination.
How do you figure out what happens? The resistor has given you one relation, but that’s not enough. There needs to be some other constraint.
That constraint comes from the characteristics of what the resistor is connected to:
- if it’s connected to an ideal battery, the voltage can’t change, so the current will.
- if connected to an ideal current source, the current can’t change, so the voltage will
- and in others, the voltage and resistance of the connected circuit will determine the mix of V and I changes