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I often see overhead power lines without any shielding from the elements. Are these lines galvanized or does current protect them from corrosion? Wouldn't the electron flow through the metal wires prevent oxygen from bonding to it? At the same time, however, you could claim it would have no effect. The corrosive elements, air, water, etc, do not have the same voltage reference.
Finally, can carefully limited electric current be used as an anti-corrosion method?
I would say that both answers are wrong. Imagine if the inductor were omitted from the circuit and any source of voltage or current were applied (via the 3 ohm series resistor) to what is basically a balanced bridge.
What would be the voltage at the junction of the two 1 ohm resistors - it would be the same voltage as at the junction of the two 3 ohm resistors - net voltage across the two points (where the inductor was connected) is always zero.
So, now replace the inductor and ask yourself what the net voltage across the inductor will be - it'll still be zero and never, ever will any current flow thru it.
There is nothing "magic" about ground. It is just another route for current to get to its destination.
In most small signal circuits like you have shown the ground symbols are just a way of connecting points together without actually drawing the wires. The ground symbols also act as a reference point against which other voltages can be measured.
For instance, these two circuits are identical:
simulate this circuit – Schematic created using CircuitLab
When you have real earth in there, the circuit is slightly modified to be more like:
The key point is that the current flows from one point of the circuit, through ground, then back into the circuit.
With only one connection to ground there is no circuit for the current to flow through. It can't flow "to" ground, because there is nowhere for it to flow to. There's no difference between ground and a wire dangling in the breeze.
Electricity flowing to ground in high voltage systems has nothing to do with the fact that they're high voltage. It's purely to do with there being a second connection to ground elsewhere in the circuit (usually at the sub-station) which forms the circuit.
You can read more on the different earthing systems on Wikipedia.
Best Answer
Current thru a metal has no effect on corrosion. However, corrosion is a electro-chemical process, so current into or out of a conductor does effect its chemical activity over surface the current flows into or out of.
This is exactly the effect galvanizing exploits to reduce corrosion of ferrous metals. The zinc coating does directly protect the metal underneath.
However, the special properties of galvanizing kick in when there is a hole in the zinc protective layer. Now you have zinc and iron exposed to the same electrolyte. A current will flow due to this battery. The direction of the current is such to reduce corrosion of the iron, while instead corroding the zinc.
In some cases, like off shore oil platforms for example, it is cheaper and more effective to put zinc anodes in various places than to coat the steel with zinc. One advantage is that the zinc electrodes can be periodically replaced as they get corroded away. In fact they are often referred to as sacrificial anodes. Divers going down and replacing the zinc blocks is part of routine maintenance.