To connect it to the circuit.
*to store charge. *to smooth out(reduce ripple on dc) a voltage
The main role of dielectrics in capacitors is to increase the value of capacitance of the capacitor.
We don't know much about the circuit these capacitors are in, but they are coupling capacitors. Coupling capacitors isolate DC between stages or circuits, and they couple AC between those circuits or stages. Only the signal gets in and goes out. The DC the stage operates on is isolated from stage to stage.
To determine polarity in CAPACITORS:Electrolytic capacitors are often marked with a stripe. That stripe indicates the NEGATIVE lead.If it's an axial leaded capacitor (leads come out of opposite ends of the capacitor), the stripe may be accompanied by an arrow that points to the negative lead.Sometimes, you can look to the length of the leads as an indication of polarity. The positive lead is usually longer but be careful if you're reusing old or 2nd hand capacitors - the leads may have been trimmed.Tantalum capacitors are often marked with a '+'sign.http://www.westfloridacomponents.com/polarity.html
The capacitors those are polarity sensitive are called electrolytic and tantalum capacitors. These capacitors are labeled as positive and negative.
Capacitors are rated in Microfarads
You can test a capacitor using a multimeter and two leads by placing the multimeter in ohms mode. It works best with a needle type meter, not a digital meter. Connect the leads to the capacitor and you will notice that the resistance pulses down, and then settles out at infinity. Reverse the leads, and you will notice the same effect, except that the pulse will be larger because the capacitor got charged in the opposite direction. Go back and forth. This won't be apparent for very small capacitors because the pulse is too short. Also, for electrolytic capacitors, they should only be charged in one direction, so you should start by discharging the capacitor and then connecting it in only one direction. Do not reverse the leads in this case. Just discharge and try again to see the effect. Try this for various capacitors. You will notice that the pulse duration is larger for larger capacitance.
because normal capacitors does not have any polaririties.
Film capacitors cannot be replaced with ceramic or mica capacitors if used for analog signal processing. However, mica capacitors can be replaced with ceramic capacitors in general.
Most fan capacitors are electrolytic and non-polariced. The trick is that two electrolytic capacitors are connented together in a single package. The negative terminals are connected together internally and the positive terminals form the external leads. For more information, visit books.google.co.ke.
Replaced capacitors that are no lomger capacitors.
Mostly the leakage of capacitors is due to the resistor.