Do All Capacitors Have Polarity. This is important because hooking one up backwards can be dangerous. The large 20000 µF electrolytic unit shown in the upright position has its positive terminal labeled with a plus mark.
Electrolytic and tantalum capacitors both have polarity. Aluminum caps can be marked in a number of different ways. Only capacitors that use a conductive liquid called an electrolyte are polarized.
For this reason the polarity is marked on the device housing.
The positive terminal should be connected to positive of supply and negative to negative. If the schematic symbol does not indicate a polarity then you can work on the assumption that any of the given capacitors could have either a positive or negative voltage if the sources were ac sources which they are not. My understanding is that AC capacitors dont have a polarity since AC alternates but DC capacitors have a positive and negative. Polar capacitors or polarized capacitors are such type of a capacitor whose terminals electrodes have polarity.
