Wasn't this addressed in your other thread (AC/DC caps)? Reverse biasing an electrolytic cap causes its oxide layer to dissolve and allows current to pass. For non-polarised caps the oxide layer is on both foils. The oxide layer that is destroyed by voltage in one direction can be restored when the voltage is reversed (http://en.wikipedia.org/wiki/Capacitor)So the Plates aren't polarized it's only the chemicals that are polarized?
They are more likely to be NTC/PTC devices or polyswitches that are in series with the supply; varistors are not used in that mode. PTC/polyswitches will have an increase in their resistance as their temperature increases, which means that they can be used in place of fuses to protect/disconnect against overcurrent. An NTC device will decrease its resistance as its temperature is increased, which makes it suitable for limiting the inrush current (current when first powered up).I do see Varistors in series with a bank of electrolytic caps in power supplies, why do they use these Varistors? it limits the current at a certain voltage right? These Varistors will Open if there is a SHORT or drawing to much current from the power supply right?
If you do see a varistor (MOV), they will be connected across (in parallel with) the circuit to be protected. If their characteristic voltage is exceeded, they will conduct (similar [but different] to a zener diode; see http://en.wikipedia.org/wiki/Varistor)
That may be the case, but it may have other uses also (inrush limiting, current sensing, snubbing, etc.); it depends on where it is and what's around it.I also see a 1 ohm resistor on the return path going to ground, I'm guessing these 1 ohm resistors are used a fuses if there is a DIRECT short from VCC to ground the 1 ohm resistor will open on the return path going to ground