rajpurkar/squad huggingface dataset:
Title: Capacitor

The arrangement of plates and dielectric has many variations depending on the desired ratings of the capacitor. For small values of capacitance (microfarads and less), ceramic disks use metallic coatings, with wire leads bonded to the coating. Larger values can be made by multiple stacks of plates and disks. Larger value capacitors usually use a metal foil or metal film layer deposited on the surface of a dielectric film to make the plates, and a dielectric film of impregnated paper or plastic – these are rolled up to save space. To reduce the series resistance and inductance for long plates, the plates and dielectric are staggered so that connection is made at the common edge of the rolled-up plates, not at the ends of the foil or metalized film strips that comprise the plates.

Question: What order of magnitude of capacitance is suitable for capacitors comprised of ceramic disks with metallic coatings?
Answer: microfarads and less

Question: How are larger value capacitors often constructed?
Answer: multiple stacks of plates and disks

Question: What do larger value capacitors often use as the dielectric medium?
Answer: impregnated paper or plastic – these are rolled up to save space

Question: Why are the plates and dielectrics often staggered in larger value capacitors?
Answer: To reduce the series resistance and inductance

Question: How are the conductive plates often made for larger value capacitors?
Answer: metal film layer deposited on the surface of a dielectric film
Title: Capacitor

Capacitors may have their connecting leads arranged in many configurations, for example axially or radially. "Axial" means that the leads are on a common axis, typically the axis of the capacitor's cylindrical body – the leads extend from opposite ends. Radial leads might more accurately be referred to as tandem; they are rarely actually aligned along radii of the body's circle, so the term is inexact, although universal. The leads (until bent) are usually in planes parallel to that of the flat body of the capacitor, and extend in the same direction; they are often parallel as manufactured.

Question: What is one type of configuration in which a capacitor may have its connecting leads organized?
Answer: axially

Question: What is another type of configuration in which a capacitor may have its connecting leads arranged?
Answer: radially

Question: Which type of configuration is often manufactured with the leads parallel to the body of the capacitor?
Answer: Radial

Question: How are the leads of an axially configured capacitor arranged?
Answer: on a common axis

Question: How could radial leads be more correctly described?
Answer: as tandem
Title: Capacitor

Small, cheap discoidal ceramic capacitors have existed since the 1930s, and remain in widespread use. Since the 1980s, surface mount packages for capacitors have been widely used. These packages are extremely small and lack connecting leads, allowing them to be soldered directly onto the surface of printed circuit boards. Surface mount components avoid undesirable high-frequency effects due to the leads and simplify automated assembly, although manual handling is made difficult due to their small size.

Question: Since when have inexpensive ceramic disc capacitors existed?
Answer: the 1930s

Question: Since when have surface mount packages for capacitors been commonly in use?
Answer: the 1980s

Question: What do surface mount packages lack that allows their use on the surface of printed circuit boards?
Answer: connecting leads

Question: What is one benefit of using surface mount components?
Answer: simplify automated assembly

Question: What is one difficulty when using surface mount components?
Answer: manual handling is made difficult due to their small size
Title: Capacitor

Mechanically controlled variable capacitors allow the plate spacing to be adjusted, for example by rotating or sliding a set of movable plates into alignment with a set of stationary plates. Low cost variable capacitors squeeze together alternating layers of aluminum and plastic with a screw. Electrical control of capacitance is achievable with varactors (or varicaps), which are reverse-biased semiconductor diodes whose depletion region width varies with applied voltage. They are used in phase-locked loops, amongst other applications.

Question: What do mechanically controlled variable capacitors enable to be modified?
Answer: the plate spacing

Question: How do cheap variable capacitors vary the separation distance between layers of a plastic and aluminum?
Answer: with a screw

Question: Of what type of diodes are varactors or varicaps comprised?
Answer: reverse-biased semiconductor diodes

Question: What varies as a function of voltage in varactors?
Answer: depletion region

Question: What is an application of varactors?
Answer: phase-locked loops
Title: Capacitor

Most capacitors have numbers printed on their bodies to indicate their electrical characteristics. Larger capacitors like electrolytics usually display the actual capacitance together with the unit (for example, 220 μF). Smaller capacitors like ceramics, however, use a shorthand consisting of three numeric digits and a letter, where the digits indicate the capacitance in pF (calculated as XY × 10Z for digits XYZ) and the letter indicates the tolerance (J, K or M for ±5%, ±10% and ±20% respectively).

Question: How do larger capacitors present their electrical characteristics?
Answer: display the actual capacitance together with the unit (for example, 220 μF)

Question: What does the abbreviated electrical characteristics of smaller capacitors consist of?
Answer: three numeric digits and a letter

Question: What part of the electrical characteristics of smaller capacitors do the digits of the abbreviated notation represent ?
Answer: the digits indicate the capacitance

Question: What does the letter of the abbreviated notation for the electrical characteristics of smaller capacitors represent?
Answer: the letter indicates the tolerance

Question: In what SI unit is the capacitance reported on smaller capacitors?
Answer: in pF
Title: Capacitor

Capacitors are connected in parallel with the power circuits of most electronic devices and larger systems (such as factories) to shunt away and conceal current fluctuations from the primary power source to provide a "clean" power supply for signal or control circuits. Audio equipment, for example, uses several capacitors in this way, to shunt away power line hum before it gets into the signal circuitry. The capacitors act as a local reserve for the DC power source, and bypass AC currents from the power supply. This is used in car audio applications, when a stiffening capacitor compensates for the inductance and resistance of the leads to the lead-acid car battery.

Question: Why are capacitors connected in parallel with the power circuits of many devices and large systems?
Answer: to provide a "clean" power supply for signal or control circuits

Question: How do the capacitors connected in parallel act with currents from the power supply?
Answer: as a local reserve for the DC power source

Question: What is one value a stiffening capacitor accounts for when used in for car audio purposes?
Answer: the inductance

Question: What is another value a stiffening capacitor accounts for when used in for car audio purposes?
Answer: resistance

Question: What do parallel capacitors do to fluctuating current in order to deliver "clean" power for control circuits?
Answer: conceal current fluctuations
Title: Capacitor

In electric power distribution, capacitors are used for power factor correction. Such capacitors often come as three capacitors connected as a three phase load. Usually, the values of these capacitors are given not in farads but rather as a reactive power in volt-amperes reactive (var). The purpose is to counteract inductive loading from devices like electric motors and transmission lines to make the load appear to be mostly resistive. Individual motor or lamp loads may have capacitors for power factor correction, or larger sets of capacitors (usually with automatic switching devices) may be installed at a load center within a building or in a large utility substation.

Question: In what scenario are capacitors used for power factor correction?
Answer: In electric power distribution

Question: How are capacitors used for for power factor correction prepared?
Answer: as three capacitors connected as a three phase load

Question: In what what unit is the capacitance reported for capacitors used in power factor correction?
Answer: reactive power in volt-amperes reactive (var)

Question: What is the reason for using capacitors in power factor correction?
Answer: to counteract inductive loading

Question: How are power factor correction capacitors sometimes installed?
Answer: at a load center within a building
Title: Capacitor

When an inductive circuit is opened, the current through the inductance collapses quickly, creating a large voltage across the open circuit of the switch or relay. If the inductance is large enough, the energy will generate a spark, causing the contact points to oxidize, deteriorate, or sometimes weld together, or destroying a solid-state switch. A snubber capacitor across the newly opened circuit creates a path for this impulse to bypass the contact points, thereby preserving their life; these were commonly found in contact breaker ignition systems, for instance. Similarly, in smaller scale circuits, the spark may not be enough to damage the switch but will still radiate undesirable radio frequency interference (RFI), which a filter capacitor absorbs. Snubber capacitors are usually employed with a low-value resistor in series, to dissipate energy and minimize RFI. Such resistor-capacitor combinations are available in a single package.

Question: What happens to the current when an inductive circuit is opened?
Answer: the current through the inductance collapses quickly

Question: What happens to the voltage when an inductive circuit is opened?
Answer: a large voltage across the open circuit of the switch

Question: What type of capacitor is used to make a path to bypass the contact points?
Answer: A snubber capacitor

Question: What is a typical system in which a snubber capacitor is found?
Answer: contact breaker ignition systems

Question: What type of capacitor absorbs radio frequency interference?
Answer: a filter capacitor
Title: Capacitor

In single phase squirrel cage motors, the primary winding within the motor housing is not capable of starting a rotational motion on the rotor, but is capable of sustaining one. To start the motor, a secondary "start" winding has a series non-polarized starting capacitor to introduce a lead in the sinusoidal current. When the secondary (start) winding is placed at an angle with respect to the primary (run) winding, a rotating electric field is created. The force of the rotational field is not constant, but is sufficient to start the rotor spinning. When the rotor comes close to operating speed, a centrifugal switch (or current-sensitive relay in series with the main winding) disconnects the capacitor. The start capacitor is typically mounted to the side of the motor housing. These are called capacitor-start motors, that have relatively high starting torque. Typically they can have up-to four times as much starting torque than a split-phase motor and are used on applications such as compressors, pressure washers and any small device requiring high starting torques.

Question: What is the main winding on a squirrel cage motor capable of withstanding?
Answer: a rotational motion on the rotor

Question: What sort of capacitors are used on the second winding of a squirrel cage motor?
Answer: series non-polarized starting capacitor

Question: What does the capacitor on the second winding of a squirrel cage motor do?
Answer: introduce a lead in the sinusoidal current

Question: What does the centrifugal switch do the capacitor when the rotor achieves operating speed?
Answer: disconnects the capacitor

Question: Where is the start capacitor commonly mounted?
Answer: to the side of the motor housing
Title: Capacitor

Capacitors may retain a charge long after power is removed from a circuit; this charge can cause dangerous or even potentially fatal shocks or damage connected equipment. For example, even a seemingly innocuous device such as a disposable-camera flash unit, powered by a 1.5 volt AA battery, has a capacitor which may contain over 15 joules of energy and be charged to over 300 volts. This is easily capable of delivering a shock. Service procedures for electronic devices usually include instructions to discharge large or high-voltage capacitors, for instance using a Brinkley stick. Capacitors may also have built-in discharge resistors to dissipate stored energy to a safe level within a few seconds after power is removed. High-voltage capacitors are stored with the terminals shorted, as protection from potentially dangerous voltages due to dielectric absorption or from transient voltages the capacitor may pick up from static charges or passing weather events.

Question: How much energy could a capacitor in a disposable camera contain?
Answer: over 15 joules of energy

Question: To what voltage could a capacitor from a disposable camera be charged to?
Answer: over 300 volts

Question: What device can be used to discharge large voltage capacitors?
Answer: a Brinkley stick

Question: How are the terminals of high voltage capacitors stored?
Answer: with the terminals shorted

Question: What type of charge could a capacitor pick up a transient charge from?
Answer: from static charges
Title: Capacitor

Capacitors may catastrophically fail when subjected to voltages or currents beyond their rating, or as they reach their normal end of life. Dielectric or metal interconnection failures may create arcing that vaporizes the dielectric fluid, resulting in case bulging, rupture, or even an explosion. Capacitors used in RF or sustained high-current applications can overheat, especially in the center of the capacitor rolls. Capacitors used within high-energy capacitor banks can violently explode when a short in one capacitor causes sudden dumping of energy stored in the rest of the bank into the failing unit. High voltage vacuum capacitors can generate soft X-rays even during normal operation. Proper containment, fusing, and preventive maintenance can help to minimize these hazards.

Question: What could cause the failure of a capacitor?
Answer: when subjected to voltages or currents beyond their rating

Question: What can happen to capacitors used in high current applications?
Answer: overheat

Question: What can happen to capacitors used in high energy capacitor banks?
Answer: violently explode

Question: What type of capacitors can generate soft x-rays?
Answer: High voltage vacuum capacitors

Question: What is one way to help minimize capacitor dangers?
Answer: preventive maintenance
Title: History_of_science

The history of science is the study of the development of science and scientific knowledge, including both the natural sciences and social sciences. (The history of the arts and humanities is termed as the history of scholarship.) Science is a body of empirical, theoretical, and practical knowledge about the natural world, produced by scientists who emphasize the observation, explanation, and prediction of real world phenomena. Historiography of science, in contrast, often draws on the historical methods of both intellectual history and social history.

Question: What are natural and social sciences a subcategory of?
Answer: The history of science

Question: What is the history of arts and humanities called?
Answer: the history of scholarship

Question: What kind of phenomena does science study?
Answer: real world

Question: Intellectual history and social history are used in what?
Answer: Historiography of science
Title: History_of_science

The English word scientist is relatively recent—first coined by William Whewell in the 19th century. Previously, people investigating nature called themselves natural philosophers. While empirical investigations of the natural world have been described since classical antiquity (for example, by Thales, Aristotle, and others), and scientific methods have been employed since the Middle Ages (for example, by Ibn al-Haytham, and Roger Bacon), the dawn of modern science is often traced back to the early modern period and in particular to the scientific revolution that took place in 16th- and 17th-century Europe. Scientific methods are considered to be so fundamental to modern science that some consider earlier inquiries into nature to be pre-scientific. Traditionally, historians of science have defined science sufficiently broadly to include those inquiries.

Question: Who coined the word "scientist"?
Answer: William Whewell

Question: When was the word "scientist" created?
Answer: 19th century

Question: What are people who study nature called?
Answer: natural philosophers

Question: Ibn al-Haytham and Roger Bacon were scientists in which time period?
Answer: the Middle Ages

Question: When was the beginning of modern science considered to be?
Answer: the scientific revolution
Title: History_of_science

From the 18th century through late 20th century, the history of science, especially of the physical and biological sciences, was often presented in a progressive narrative in which true theories replaced false beliefs. More recent historical interpretations, such as those of Thomas Kuhn, tend to portray the history of science in different terms, such as that of competing paradigms or conceptual systems in a wider matrix that includes intellectual, cultural, economic and political themes outside of science.

Question: What replaced false beliefs?
Answer: true theories

Question: Who depicts the history of science in a wider matrix?
Answer: Thomas Kuhn

Question: What time period did the history of science begin to take a progressive narrative?
Answer: the 18th century

Question: Thomas Kuhn used conceptual systems and what other term to define the history of science?
Answer: competing paradigms
Title: History_of_science

The development of writing enabled knowledge to be stored and communicated across generations with much greater fidelity. Combined with the development of agriculture, which allowed for a surplus of food, it became possible for early civilizations to develop, because more time and effort could be devoted to tasks (other than food production) than hunter-gatherers or early subsistence farmers had available. This surplus allowed a community to support individuals who did things other than work towards bare survival. These other tasks included systematic studies of nature, study of written information gathered and recorded by others, and often of adding to that body of information.

Question: The advancement of agriculture made what possible?
Answer: a surplus of food

Question: Having a surplus of food allowed farmers and hunter-gatherers to spend less time working on what?
Answer: food production

Question: Before agriculture advancements, what were farmers having to do?
Answer: work towards bare survival

Question: What advancement aided in spreading knowledge across generations?
Answer: The development of writing

Question: Who was able to support the people who were adding to the written knowledge of nature?
Answer: community
Title: History_of_science

Ancient Egypt made significant advances in astronomy, mathematics and medicine. Their development of geometry was a necessary outgrowth of surveying to preserve the layout and ownership of farmland, which was flooded annually by the Nile river. The 3-4-5 right triangle and other rules of thumb were used to build rectilinear structures, and the post and lintel architecture of Egypt. Egypt was also a center of alchemy research for much of the Mediterranean.The Edwin Smith papyrus is one of the first medical documents still extant, and perhaps the earliest document that attempts to describe and analyse the brain: it might be seen as the very beginnings of modern neuroscience. However, while Egyptian medicine had some effective practices, it was not without its ineffective and sometimes harmful practices. Medical historians believe that ancient Egyptian pharmacology, for example, was largely ineffective. Nevertheless, it applies the following components to the treatment of disease: examination, diagnosis, treatment, and prognosis, which display strong parallels to the basic empirical method of science and according to G. E. R. Lloyd played a significant role in the development of this methodology. The Ebers papyrus (c. 1550 BC) also contains evidence of traditional empiricism.

Question: Which civilization advanced in astronomy, mathematics, and medicine?
Answer: Ancient Egypt

Question: What did Egyptians use to better organize their farmland?
Answer: geometry

Question: What theory did the Egyptians use to build rectilinear structures?
Answer: The 3-4-5 right triangle

Question: What research was Egypt known for?
Answer: alchemy

Question: What is the name of the earliest medical document?
Answer: The Edwin Smith papyrus
Title: History_of_science

From their beginnings in Sumer (now Iraq) around 3500 BC, the Mesopotamian people began to attempt to record some observations of the world with numerical data. But their observations and measurements were seemingly taken for purposes other than for elucidating scientific laws. A concrete instance of Pythagoras' law was recorded, as early as the 18th century BC: the Mesopotamian cuneiform tablet Plimpton 322 records a number of Pythagorean triplets (3,4,5) (5,12,13). ..., dated 1900 BC, possibly millennia before Pythagoras,  but an abstract formulation of the Pythagorean theorem was not.

Question: Where did the Mesopotamian people originate from?
Answer: Sumer

Question: How far back do the Mesopotamian people go?
Answer: 3500 BC

Question: What did the Mesopotamian use to record data about the world around them?
Answer: numerical data

Question: What was the earliest recording of Pythagoras' law?
Answer: 18th century BC

Question: Which tablet had Pythagorean triplets on it?
Answer: Plimpton 322
Title: History_of_science

In Babylonian astronomy, records of the motions of the stars, planets, and the moon are left on thousands of clay tablets created by scribes. Even today, astronomical periods identified by Mesopotamian proto-scientists are still widely used in Western calendars such as the solar year and the lunar month. Using these data they developed arithmetical methods to compute the changing length of daylight in the course of the year and to predict the appearances and disappearances of the Moon and planets and eclipses of the Sun and Moon. Only a few astronomers' names are known, such as that of Kidinnu, a Chaldean astronomer and mathematician. Kiddinu's value for the solar year is in use for today's calendars. Babylonian astronomy was "the first and highly successful attempt at giving a refined mathematical description of astronomical phenomena." According to the historian A. Aaboe, "all subsequent varieties of scientific astronomy, in the Hellenistic world, in India, in Islam, and in the West—if not indeed all subsequent endeavour in the exact sciences—depend upon Babylonian astronomy in decisive and fundamental ways."

Question: Who wrote on the clay tablets in Babylonian astronomy?
Answer: scribes

Question: Where are Mesopotamian astronomical periods still used?
Answer: in Western calendars

Question: Who was Kidinnu?
Answer: a Chaldean astronomer and mathematician

Question: Who believes that the Hellenistic world relies on Babylonian astronomy?
Answer: A. Aaboe

Question: Where can Kidinnu's solar year be found in use?
Answer: today's calendars