Question: What is the name of the insulator in all capacitors that can store energy by becoming polarized?
Answer: a dielectric

Question: In what form does a capacitor store energy?
Answer: the form of an electrostatic field

Question: Where is the energy stored by a capacitor located?
Answer: between its plates

Question: When does an electric field develop across the dielectric?
Answer: When there is a potential difference across the conductors

Question: Under what condition can a displacement current flow in a capacitor?
Answer: if a time-varying voltage is applied across the leads

Question: What is an example of when there exists a potential difference across the conductors? 
Answer: when a capacitor is attached across a battery

Question: What happens to the current when a battery has been attached to a capacitor for an adequate amount of time?
Answer: no current can flow through the capacitor

Question: How do charges accumulate on each plate of a capacitor after an electric field has developed across the dielectric?
Answer: positive charge +Q to collect on one plate and negative charge −Q to collect on the other

Question: Who first discovered the basic properties of capacitors?
Answer: Ewald Georg von Kleist

Question: When were the basic properties of capacitors first discovered?
Answer: In October 1745

Question: In the original experiment in which the properties of capacitors were discovered, what component acted as the dielectric? 
Answer: a hand-held glass jar

Question: Besides the scientist's hand, what other component of the experiment in which the basic properties of capacitors were discovered acted as the second conductor?
Answer: the water acted as conductors

Question: What was the name of the Dutch physicist who invented the Leyden Jar?
Answer: Pieter van Musschenbroek

Question: Who was the first person to connect several Leyden jars in parallel?
Answer: Daniel Gralath

Question: Where did Benjamin Franklin believe the charge was stored in Leyden jars?
Answer: stored on the glass

Question: Who coined the term "battery"?
Answer: Benjamin Franklin

Question: How many nanofarads did the earliest unit of capacitance equate to? 
Answer: 1.11 nanofarads

Question: Why was a gap left at the mouth of Leyden jars?
Answer: to prevent arcing between the foils

Question: Besides porcelain, paper and mica, what other non conductive material was used as an insulator? 
Answer: glass

Question: For what use were non conductive materials used in the first capacitors?
Answer: as the dielectric

Question: What was layered between strips of metal in order to create paper capacitors?
Answer: strip of impregnated paper

Question: When were paper capacitors first manufactured?
Answer: in 1876

Question: What other use did paper capacitors serve in the telecommunications industry?
Answer: as decoupling capacitors

Question: Who invented the first electrolytic capacitor?
Answer: Charles Pollak

Question: In what sort of electrolyte does the oxide layer on an aluminum anode remain stable?
Answer: a neutral or alkaline electrolyte

Question: In what year was the patent filed for an electric liquid capacitor?
Answer: In 1896

Question: What sort of capacitors were created by Bell Labs in the 1950's?
Answer: Solid electrolyte tantalum capacitors

Question: Why did Bell labs create their new type of capacitor?
Answer: to complement their newly invented transistor

Question: What are electric double-layer capacitors called today?
Answer: Supercapacitors

Question: When were low voltage electrolytic capacitors with porous carbon electrodes invented?
Answer: In 1957

Question: Who invented low voltage electrolytic capacitors with porous carbon electrodes?
Answer: H. Becker

Question: In what part of the capacitor did Becker believe the charge was being stored?
Answer: in the carbon pores

Question: In what component of electrolytic capacitors did Becker believe was similar to the porous carbon electrodes?
Answer: the pores of the etched foils

Question: What type of area is between the two conductors in a capacitor?
Answer: a non-conductive region

Question: What is the name given to the area between two conductors in a capacitor?
Answer: the dielectric

Question: What net electric charge are capacitors assumed to have?
Answer: no net electric charge

Question: What type of charges do conductors hold on their facing surfaces?
Answer: equal and opposite charges

Question: What region within a capacitor develops an electric field?
Answer: the dielectric

Question: What is the definition of the current I(t) through any component in an electric circuit?
Answer: the rate of flow of a charge Q(t) passing through it

Question: For each electron that departs the positive plate, how many electrons build up on the negative plate?
Answer: one electron accumulates on the negative plate

Question: To what is the charge on the electrodes of a capacitor equal to?
Answer: the integral of the current

Question: To what is the charge on the electrodes of a capacitor proportional to?
Answer: proportional to the voltage

Question: When calculating the integral to determine the charge on the electrodes of a capacitor, what does the constant of integration that must be added represent?
Answer: the initial voltage V(t0)

Question: In an ideal model of a capacitor, what is the value that describes the permittivity of the dielectric?
Answer: permittivity ε

Question: What equation describes the charge density for an ideal model of a capacitor?
Answer: ±ρ = ±Q/A

Question: In an ideal model of a capacitor, what must be assumed about the size of the plates?
Answer: much greater than their separation d

Question: Close to the middle of the capacitor, what equation describes the magnitude of the electric field?
Answer: E = ρ/ε

Question: What does the line integral of the electric field between the plates of a capacitor represent?
Answer: The voltage

Question: What is a function of the amount of dielectric, the strength of dielectric and its permittivity?
Answer: The maximum energy

Question: If the plate area and separation distance are altered while keeping the amount of dielectric the same, what effect is had on the maximum energy of the capacitor? 
Answer: no change of the maximum amount of energy

Question: In a realistic model of a capacitor, where else besides between the dielectric between the conductors might an electric field be found?
Answer: fringing fields outside the dielectric

Question: When an electric field exists between the sides of the plates as well as in within the dielectric, what effect is had on the effective capacitance of the capacitor?
Answer: will increase the effective capacitance

Question: When the ratios of plate length and width to separation distance are large, what size is the parasitic capacitance?
Answer: negligibly small

Question: What characteristic can leakage current and parasitic effects be assumed to have in the equation for a realistic capacitor?
Answer: can be assumed to be linear

Question: What sort of components can be added to the equivalent circuit of a capacitor in order to deal with leakage current and parasitic effects?
Answer: virtual components

Question: Upon dealing with leakage current and parasitic effects in a realistic model of a capacitor, what sort of methods can then be applied?
Answer: The usual methods of network analysis

Question: What sort of analysis cannot be used in cases of voltage breakdown in modelling a capacitor?
Answer: normal (i.e., linear) network analysis cannot be used

Question: What causes the assumption of constant capacitance to fail even if the effect is linear in nature?
Answer: temperature dependence

Question: What order is the breakdown field strength for air dielectric capacitors of?
Answer: of the order 2 to 5 MV/m

Question: Of what order is the breakdown field strength for mica dielectric capacitors?
Answer: 100 to 300 MV/m