There are 2 main types of capacitors:

Non-polarized fixed capacitor

A non-polarized ("non polar") capacitor is a type of capacitor that has no implicit polarity -- it can be connected either way in a circuit. Ceramic, mica and some electrolytic capacitors are non-polarized. You'll also sometimes hear people call them "bipolar" capacitors.

Polarized fixed capacitor

A polarized ("polar") capacitor is a type of capacitor that have implicit polarity -- it can only be connected one way in a circuit. The positive lead is shown on the schematic (and often on the capacitor) with a little "+" symbol. The negative lead is generally not shown on the schematic, but may be marked on the capacitor with a bar or "-" symbol. Polarized capacitors are generally electrolytics.

Note that you really need to pay attention to correctly hooking a polarized capacitor up (both with respect to polarity, as well as not pushing a capacitor past its rated voltage). If you "push" a polarized capacitor hard enough, it is possible to begin "electrolyzing" the moist electrolyte. Modern electrolytic capacitors usually have a pressure relief vent to prevent catastrophic failure of the aluminum can (but don't bet your eyesight on this).

I hope this help

There are 2 main types of capacitors:

Non-polarized fixed capacitor

A non-polarized ("non polar") capacitor is a type of capacitor that has no implicit polarity -- it can be connected either way in a circuit. Ceramic, mica and some electrolytic capacitors are non-polarized. You'll also sometimes hear people call them "bipolar" capacitors.

Polarized fixed capacitor

A polarized ("polar") capacitor is a type of capacitor that have implicit polarity -- it can only be connected one way in a circuit. The positive lead is shown on the schematic (and often on the capacitor) with a little "+" symbol. The negative lead is generally not shown on the schematic, but may be marked on the capacitor with a bar or "-" symbol. Polarized capacitors are generally electrolytics.

Note that you really need to pay attention to correctly hooking a polarized capacitor up (both with respect to polarity, as well as not pushing a capacitor past its rated voltage). If you "push" a polarized capacitor hard enough, it is possible to begin "electrolyzing" the moist electrolyte. Modern electrolytic capacitors usually have a pressure relief vent to prevent catastrophic failure of the aluminum can (but don't bet your eyesight on this).

I hope this help

Thanks for your reply, but why we use polarized capacitors? Cant the non-polarized capacitors replace them so that we don't have the problem of polarity?

You never "need" a polarized cap. Practically all physical circuits would work just as well, and perhaps better, if the polarized caps were all replaced with non-polarized caps of the same capacitance and voltage rating. The opposite is not true -- you often can't replace non-polarized caps with polarized caps. Some circuits require a capacitor that can handle a high positive voltage at some times and a high negative voltage at other times (polarity reversal), which requires a non-polarized capacitor

The only reason people use polarized caps is because they often cost much less than non-polarized caps of the same capacitance and voltage rating.

examples of non-polarized capacitors

P-C has a small size with the large capacitance, is used only in DC circuits or circuits related to DC current.

P-C has a large leakage current, low frequency response - only up to about tens of kHz at aluminum or 1MHz at tantalium caps.

NP-C has a big size with the smaller capacitance, is used both in DC or AC circuits, low or high frequencies.

NP-C has a very small leakage current, high frequency response - up to hundreds of GHz up to types.

In general, they cannot replace for each other.

Sometimes, in household appliance in frequency of 50/60Hz, they can use 2 P-C caps (with capacitance doubled of the NP-C) connected in series by opposite terminals (and diodes in parallel with each cap to protect it from reversed voltage) to replace 1 NP-C cap to save space, but this type of replacement is not strongly recommended.

* *****Polarized

higher Distortion

smaller in size

cheaper

Can not be used in AC without DC polarizing bias

Value are relatively high

***************Non Polarized

lower in Distortion

huge in size

More expensive

AC and DC

All values

Thanks...