sentence-transformers/squad huggingface dataset:
Passage: Edward Hallett Carr, a frequent defender of Soviet policy, stated: "In return for 'non-intervention' Stalin secured a breathing space of immunity from German attack."[page needed] According to Carr, the "bastion" created by means of the Pact, "was and could only be, a line of defense against potential German attack."[page needed] According to Carr, an important advantage was that "if Soviet Russia had eventually to fight Hitler, the Western Powers would already be involved."[page needed] However, during the last decades, this view has been disputed. Historian Werner Maser stated that "the claim that the Soviet Union was at the time threatened by Hitler, as Stalin supposed ... is a legend, to whose creators Stalin himself belonged. In Maser's view, "neither Germany nor Japan were in a situation [of] invading the USSR even with the least perspective [sic] of success," and this could not have been unknown to Stalin. Carr further stated that, for a long time, the primary motive of Stalin's sudden change of course was assumed to be the fear of German aggressive intentions.

Question: Edward Carr believes that in a war between Germany and the Soviet Union, who else would have been participating?

Question: Who believes that the Soviet Unions was afraid of Germany?

Question: The pact according to Edward Carr’s view was to provide what between Germany and the Soviet Union?
Passage: Some critics of Stalin's policy, such as the popular writer Viktor Suvorov, claim that Stalin's primary motive for signing the Soviet–German non-aggression treaty was his calculation that such a pact could result in a conflict between the capitalist countries of Western Europe.[citation needed] This idea is supported by Albert L. Weeks.[page needed] Claims by Suvorov that Stalin planned to invade Germany in 1941 are debated by historians with, for example, David Glantz opposing such claims, while Mikhail Meltyukhov supports them.[citation needed] The authors of The Black Book of Communism consider the pact a crime against peace and a "conspiracy to conduct war of aggression."

Question: Who was skeptical of Stalin’s policies?

Question: What is the claim the pact promoted, purported by the The Black Book of Communism?

Question: Who doesn’t believe that Joseph Stalin had plans to invade Germany?
Passage: A capacitor (originally known as a condenser) is a passive two-terminal electrical component used to store electrical energy temporarily in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors (plates) separated by a dielectric (i.e. an insulator that can store energy by becoming polarized). The conductors can be thin films, foils or sintered beads of metal or conductive electrolyte, etc. The nonconducting dielectric acts to increase the capacitor's charge capacity. Materials commonly used as dielectrics include glass, ceramic, plastic film, air, vacuum, paper, mica, and oxide layers. Capacitors are widely used as parts of electrical circuits in many common electrical devices. Unlike a resistor, an ideal capacitor does not dissipate energy. Instead, a capacitor stores energy in the form of an electrostatic field between its plates.

Question: What was a capacitor originally known as?

Question: How many electrical conductors, or plates, do all capacitors contain at a minimum?

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

Question: In what form does a capacitor store energy?

Question: Where is the energy stored by a capacitor located?
Passage: When there is a potential difference across the conductors (e.g., when a capacitor is attached across a battery), an electric field develops across the dielectric, causing positive charge +Q to collect on one plate and negative charge −Q to collect on the other plate. If a battery has been attached to a capacitor for a sufficient amount of time, no current can flow through the capacitor. However, if a time-varying voltage is applied across the leads of the capacitor, a displacement current can flow.

Question: When does an electric field develop across the dielectric?

Question: Under what condition can a displacement current flow in a capacitor?

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

Question: What happens to the current when a battery has been attached to a capacitor for an adequate amount of time?

Question: How do charges accumulate on each plate of a capacitor after an electric field has developed across the dielectric?
Passage: In October 1745, Ewald Georg von Kleist of Pomerania, Germany, found that charge could be stored by connecting a high-voltage electrostatic generator by a wire to a volume of water in a hand-held glass jar. Von Kleist's hand and the water acted as conductors, and the jar as a dielectric (although details of the mechanism were incorrectly identified at the time). Von Kleist found that touching the wire resulted in a powerful spark, much more painful than that obtained from an electrostatic machine. The following year, the Dutch physicist Pieter van Musschenbroek invented a similar capacitor, which was named the Leyden jar, after the University of Leiden where he worked. He also was impressed by the power of the shock he received, writing, "I would not take a second shock for the kingdom of France."

Question: Who first discovered the basic properties of capacitors?

Question: When were the basic properties of capacitors first discovered?

Question: In the original experiment in which the properties of capacitors were discovered, what component acted as the dielectric?

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?

Question: What was the name of the Dutch physicist who invented the Leyden Jar?
Passage: Daniel Gralath was the first to combine several jars in parallel into a "battery" to increase the charge storage capacity. Benjamin Franklin investigated the Leyden jar and came to the conclusion that the charge was stored on the glass, not in the water as others had assumed. He also adopted the term "battery", (denoting the increasing of power with a row of similar units as in a battery of cannon), subsequently applied to clusters of electrochemical cells. Leyden jars were later made by coating the inside and outside of jars with metal foil, leaving a space at the mouth to prevent arcing between the foils.[citation needed] The earliest unit of capacitance was the jar, equivalent to about 1.11 nanofarads.

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

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

Question: Who coined the term "battery"?

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

Question: Why was a gap left at the mouth of Leyden jars?
Passage: Since the beginning of the study of electricity non conductive materials like glass, porcelain, paper and mica have been used as insulators. These materials some decades later were also well-suited for further use as the dielectric for the first capacitors. Paper capacitors made by sandwiching a strip of impregnated paper between strips of metal, and rolling the result into a cylinder were commonly used in the late 19century; their manufacture started in 1876, and they were used from the early 20th century as decoupling capacitors in telecommunications (telephony).

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

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

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

Question: When were paper capacitors first manufactured?

Question: What other use did paper capacitors serve in the telecommunications industry?
Passage: Charles Pollak (born Karol Pollak), the inventor of the first electrolytic capacitors, found out that the oxide layer on an aluminum anode remained stable in a neutral or alkaline electrolyte, even when the power was switched off. In 1896 he filed a patent for an "Electric liquid capacitor with aluminum electrodes." Solid electrolyte tantalum capacitors were invented by Bell Laboratories in the early 1950s as a miniaturized and more reliable low-voltage support capacitor to complement their newly invented transistor.

Question: Who invented the first electrolytic capacitor?

Question: In what sort of electrolyte does the oxide layer on an aluminum anode remain stable?

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

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

Question: Why did Bell labs create their new type of capacitor?
Passage: Last but not least the electric double-layer capacitor (now Supercapacitors) were invented. In 1957 H. Becker developed a "Low voltage electrolytic capacitor with porous carbon electrodes". He believed that the energy was stored as a charge in the carbon pores used in his capacitor as in the pores of the etched foils of electrolytic capacitors. Because the double layer mechanism was not known by him at the time, he wrote in the patent: "It is not known exactly what is taking place in the component if it is used for energy storage, but it leads to an extremely high capacity.".

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

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

Question: Who invented low voltage electrolytic capacitors with porous carbon electrodes?

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

Question: In what component of electrolytic capacitors did Becker believe was similar to the porous carbon electrodes?
Passage: A capacitor consists of two conductors separated by a non-conductive region. The non-conductive region is called the dielectric. In simpler terms, the dielectric is just an electrical insulator. Examples of dielectric media are glass, air, paper, vacuum, and even a semiconductor depletion region chemically identical to the conductors. A capacitor is assumed to be self-contained and isolated, with no net electric charge and no influence from any external electric field. The conductors thus hold equal and opposite charges on their facing surfaces, and the dielectric develops an electric field. In SI units, a capacitance of one farad means that one coulomb of charge on each conductor causes a voltage of one volt across the device.

Question: What type of area is between the two conductors in a capacitor?

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

Question: What net electric charge are capacitors assumed to have?

Question: What type of charges do conductors hold on their facing surfaces?

Question: What region within a capacitor develops an electric field?
Passage: The current I(t) through any component in an electric circuit is defined as the rate of flow of a charge Q(t) passing through it, but actual charges—electrons—cannot pass through the dielectric layer of a capacitor. Rather, one electron accumulates on the negative plate for each one that leaves the positive plate, resulting in an electron depletion and consequent positive charge on one electrode that is equal and opposite to the accumulated negative charge on the other. Thus the charge on the electrodes is equal to the integral of the current as well as proportional to the voltage, as discussed above. As with any antiderivative, a constant of integration is added to represent the initial voltage V(t0). This is the integral form of the capacitor equation:

Question: What is the definition of the current I(t) through any component in an electric circuit?

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

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

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

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?
Passage: The simplest model capacitor consists of two thin parallel conductive plates separated by a dielectric with permittivity ε . This model may also be used to make qualitative predictions for other device geometries. The plates are considered to extend uniformly over an area A and a charge density ±ρ = ±Q/A exists on their surface. Assuming that the length and width of the plates are much greater than their separation d, the electric field near the centre of the device will be uniform with the magnitude E = ρ/ε. The voltage is defined as the line integral of the electric field between the plates

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

Question: What equation describes the charge density for an ideal model of a capacitor?

Question: In an ideal model of a capacitor, what must be assumed about the size of the plates?

Question: Close to the middle of the capacitor, what equation describes the magnitude of the electric field?

Question: What does the line integral of the electric field between the plates of a capacitor represent?
Passage: The maximum energy is a function of dielectric volume, permittivity, and dielectric strength. Changing the plate area and the separation between the plates while maintaining the same volume causes no change of the maximum amount of energy that the capacitor can store, so long as the distance between plates remains much smaller than both the length and width of the plates. In addition, these equations assume that the electric field is entirely concentrated in the dielectric between the plates. In reality there are fringing fields outside the dielectric, for example between the sides of the capacitor plates, which will increase the effective capacitance of the capacitor. This is sometimes called parasitic capacitance. For some simple capacitor geometries this additional capacitance term can be calculated analytically. It becomes negligibly small when the ratios of plate width to separation and length to separation are large.

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

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?

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

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?

Question: When the ratios of plate length and width to separation distance are large, what size is the parasitic capacitance?
Passage: Capacitors deviate from the ideal capacitor equation in a number of ways. Some of these, such as leakage current and parasitic effects are linear, or can be assumed to be linear, and can be dealt with by adding virtual components to the equivalent circuit of the capacitor. The usual methods of network analysis can then be applied. In other cases, such as with breakdown voltage, the effect is non-linear and normal (i.e., linear) network analysis cannot be used, the effect must be dealt with separately. There is yet another group, which may be linear but invalidate the assumption in the analysis that capacitance is a constant. Such an example is temperature dependence. Finally, combined parasitic effects such as inherent inductance, resistance, or dielectric losses can exhibit non-uniform behavior at variable frequencies of operation.

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

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?

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

Question: What sort of analysis cannot be used in cases of voltage breakdown in modelling a capacitor?

Question: What causes the assumption of constant capacitance to fail even if the effect is linear in nature?
Passage: For air dielectric capacitors the breakdown field strength is of the order 2 to 5 MV/m; for mica the breakdown is 100 to 300 MV/m; for oil, 15 to 25 MV/m; it can be much less when other materials are used for the dielectric. The dielectric is used in very thin layers and so absolute breakdown voltage of capacitors is limited. Typical ratings for capacitors used for general electronics applications range from a few volts to 1 kV. As the voltage increases, the dielectric must be thicker, making high-voltage capacitors larger per capacitance than those rated for lower voltages. The breakdown voltage is critically affected by factors such as the geometry of the capacitor conductive parts; sharp edges or points increase the electric field strength at that point and can lead to a local breakdown. Once this starts to happen, the breakdown quickly tracks through the dielectric until it reaches the opposite plate, leaving carbon behind and causing a short (or relatively low resistance) circuit. The results can be explosive as the short in the capacitor draws current from the surrounding circuitry and dissipates the energy.

Question: What order is the breakdown field strength for air dielectric capacitors of?

Question: Of what order is the breakdown field strength for mica dielectric capacitors?

Question: In what way is the dielectric used in order to cause the absolute breakdown voltage of capacitors to be limited?

Question: What is one factor that critically affects the breakdown voltage of the capacitor?

Question: What is the difference in the physical attributes of the dielectric used in high voltage capacitors compared to low voltage capacitors?
Passage: Ripple current is the AC component of an applied source (often a switched-mode power supply) whose frequency may be constant or varying. Ripple current causes heat to be generated within the capacitor due to the dielectric losses caused by the changing field strength together with the current flow across the slightly resistive supply lines or the electrolyte in the capacitor. The equivalent series resistance (ESR) is the amount of internal series resistance one would add to a perfect capacitor to model this. Some types of capacitors, primarily tantalum and aluminum electrolytic capacitors, as well as some film capacitors have a specified rating value for maximum ripple current.

Question: What name is given to the AC component of an applied source having either constant or alternating frequency?

Question: What is one cause of dielectric losses in a capacitor?

Question: What is another cause of dielectric losses in a capacitor?

Question: What is the name given to the amount of internal series resistance needed to add to an ideal capacitor model in order to represent the heat generated by dielectric losses?

Question: What is one type of capacitor that has a specified rating value for maximum ripple current?
Passage: The capacitance of certain capacitors decreases as the component ages. In ceramic capacitors, this is caused by degradation of the dielectric. The type of dielectric, ambient operating and storage temperatures are the most significant aging factors, while the operating voltage has a smaller effect. The aging process may be reversed by heating the component above the Curie point. Aging is fastest near the beginning of life of the component, and the device stabilizes over time. Electrolytic capacitors age as the electrolyte evaporates. In contrast with ceramic capacitors, this occurs towards the end of life of the component.

Question: What value of some capacitors decreases with age?

Question: What causes the decrease of capacitance in ceramic capacitors as they age?

Question: What is one of the most important aging factors in capacitors?

Question: What is another important factor which governs how a capacitor ages?

Question: At what point can the aging effect of a capacitor be reversed if the component is heated beyond?
Passage: Capacitors, especially ceramic capacitors, and older designs such as paper capacitors, can absorb sound waves resulting in a microphonic effect. Vibration moves the plates, causing the capacitance to vary, in turn inducing AC current. Some dielectrics also generate piezoelectricity. The resulting interference is especially problematic in audio applications, potentially causing feedback or unintended recording. In the reverse microphonic effect, the varying electric field between the capacitor plates exerts a physical force, moving them as a speaker. This can generate audible sound, but drains energy and stresses the dielectric and the electrolyte, if any.

Question: What is the effect called when capacitors absorb sound waves?

Question: What value of a capacitor is varied when vibration moves the conducting plates?

Question: What sort of current is induced when the capacitance of a capacitor is altered?

Question: In what type of applications is piezeoelectricity especially problematic?

Question: What is it called when a changing electric field existing between the conductive plates of a capacitor physically moves them?
Passage: In DC circuits and pulsed circuits, current and voltage reversal are affected by the damping of the system. Voltage reversal is encountered in RLC circuits that are under-damped. The current and voltage reverse direction, forming a harmonic oscillator between the inductance and capacitance. The current and voltage will tend to oscillate and may reverse direction several times, with each peak being lower than the previous, until the system reaches an equilibrium. This is often referred to as ringing. In comparison, critically damped or over-damped systems usually do not experience a voltage reversal. Reversal is also encountered in AC circuits, where the peak current will be equal in each direction.

Question: What is one type of circuit in which voltage and current reversal are affected by damping?

Question: What is another type of circuit in which voltage and current reversal are affected by damping?

Question: Under what condition does voltage reversal occur in RLC circuits?

Question: What is formed between the inductance and the capacitance when the current and the voltage switch direction?

Question: When a system is over-damped, what does it typically not experience?
Passage: For maximum life, capacitors usually need to be able to handle the maximum amount of reversal that a system will experience. An AC circuit will experience 100% voltage reversal, while under-damped DC circuits will experience less than 100%. Reversal creates excess electric fields in the dielectric, causes excess heating of both the dielectric and the conductors, and can dramatically shorten the life expectancy of the capacitor. Reversal ratings will often affect the design considerations for the capacitor, from the choice of dielectric materials and voltage ratings to the types of internal connections used.

Question: What percentage of voltage reversal does an AC circuit experience?

Question: What does voltage reversal create in the dielectric of a capacitor?

Question: What percentage of voltage reversal will an under damped DC circuit experience?

Question: What does excess electric field present in the dielectric lead to?

Question: When designing a capacitor, what is an important rating to consider?