Capacitors are used extensively in electronic gadgets like TV, Radio, Camera etc. Tuning of a particular station in radio is done through variable Capacitors. They are available in various types. Capacitor can be classified as Polarized and non polarized capacitor.
A Non polarized capacitor does not have positive or negative terminal. It can be connected either way in the circuit. Ceramic, Mica, Polyster capacitor are examples of non polarized capacitors. Ceramic capacitor is the most commonly used among them. It is small in size and has small capacity.
The symbol for non polarised capacitor is:
On the other hand, Polarised capacitors have a positive and a negative terminal. Positive terminal is slightly longer than the negative terminal. Negative terminal is also marked as ‘-‘ on the body of the capacitor. They are inserted in the circuit keeping their polarity in mind. The symbol for polarized capacitor is :
Electrolytic capacitors are polarized. They use liquid gel as dielectric between conducting plates. Electrolytic capacitors are used for relative large value of capacitance.
Some capacitors can change their value. These are called variable capacitors. They act as tuners in TV and Radio. Symbol for variable capacitors is :
All images in this blog Vandana Razdan