Capacitor construction, Physics

Capacitor construction:


Fixed capacitors usually consist of sheets of metal foil between which is sandwiched the dielectric, or alternatively the metal, such as aluminium, is deposited onto both sides of the dielectric. The characteristics and quality of the capacitor depends mainly on the dielectric, which may be paper, chemically impregnated paper, plastics mica or ceramic.


Variable capacitors are usually meter plates with air as the dielectric. The variation is achieved by varying the area of overlap of the plates.
Preset capacitors may use air, mica or ceramics as the dielectric.


Electrolytic capacitors use the metal oxide as the dielectric which is formed directly on the metal plates. High values of capacitance can be achieved here with small physical size. Most electrolytic capacitors must be connected into circuit with the correct polarity or damage (possibly including explosion) may result.


The safe working voltage is the maximum d.c. voltage that can safely be applied to a capacitor without causing the dielectric to break down.

When breakdown occurs, the electric field is strong enough to ‘tear' electrons free from their orbits. A current then flows with the production of a large amount of heat. The dielectric is commonly burned through rendering the capacitor unserviceable.
Higher voltage require thicker dielectrics, but this reduces capacitance. Thus, a given value of capacitance requires a larger capacitor (greater plate area ‘a') for greater voltage working.


Posted Date: 9/13/2012 4:22:01 AM | Location : United States

Related Discussions:- Capacitor construction, Assignment Help, Ask Question on Capacitor construction, Get Answer, Expert's Help, Capacitor construction Discussions

Write discussion on Capacitor construction
Your posts are moderated
Related Questions
Q. What are secondary cells? Give an example? i) They are rechargeable. ii) The chemical reactions which take place in secondary cells are reversible. iii) The active mat

Define Wave Length Wave Length : The distance travel by a wave during the interval in which the particle of the medium done on vibration is called wavelength

For an enzyme that follows Michealis-Menten kinetics, the initial velocity at different substrate concentration has been determined. [S] (mM) 0.1 0

Task description You are tasked with completing the preliminary design of a plant for the production of dimethyl ether from methanol. This task involves a complete material and

Why dc ammeter cant read ac current

Can you give the S.I unit of electric displacement vector?

Beats: The periodic vibrations in intensity or loudness of sound because of superposition of two sound waves of similar amplitude and slightly different frequencies are known a

Although one of the easiest methods for verifies the value of g at a place a simple pendulum suffers from a number of limitations, the more significant of which are the following:

What is quantisation of electric charge?

DEFORMATION IN A REAL BODY DUE TO APPLICATION OF FORCE The idea of a hard body, where the constituent molecules are fixed with respect to each other, is theoretical. Till how we