Hello again,
I think Eric's example of the incandescent bulb is a good one to look at.
The true relationship between E and I is exponential like:
r=A*v^B {note v is a variable here}
yes we still call it 'ohmic' sometimes because it dissipates power as heat.
But it doesnt follow Ohm's Law until we force it to by linearizing the curve at one particular voltage point for example:
Rv=A*B*I^(B-1) {note I is a constant here}
and now we assume it obeys Ohm's Law over a small operating range:
E=I*Rv
But in this case we forced it to obey Ohm's Law and realize that this will only hold over a short range of I.
However, the device dissipates power over the entire range so sometimes we call it ohmic anyway because resistance is an energy dissipator. Perhaps a better terminology would be to simply call it 'resistive'.
I think Eric's example of the incandescent bulb is a good one to look at.
The true relationship between E and I is exponential like:
r=A*v^B {note v is a variable here}
yes we still call it 'ohmic' sometimes because it dissipates power as heat.
But it doesnt follow Ohm's Law until we force it to by linearizing the curve at one particular voltage point for example:
Rv=A*B*I^(B-1) {note I is a constant here}
and now we assume it obeys Ohm's Law over a small operating range:
E=I*Rv
But in this case we forced it to obey Ohm's Law and realize that this will only hold over a short range of I.
However, the device dissipates power over the entire range so sometimes we call it ohmic anyway because resistance is an energy dissipator. Perhaps a better terminology would be to simply call it 'resistive'.