praj-17/QA-MCQ-Open-ended huggingface dataset:
Title: Planck_constant
Context: There are both practical and theoretical difficulties in determining h. The practical difficulties can be illustrated by the fact that the two most accurate methods, the watt balance and the X-ray crystal density method, do not appear to agree with one another. The most likely reason is that the measurement uncertainty for one (or both) of the methods has been estimated too low – it is (or they are) not as precise as is currently believed – but for the time being there is no indication which method is at fault.

question: What is a main practical difficulty in determining n? 

answer: the two most accurate methods, the watt balance and the X-ray crystal density method, do not appear to agree with one another

question: Why does this difficulty occur? 

answer: it is (or they are) not as precise as is currently believed

question: Which method is at fault or the discrepancy? 

answer: there is no indication which method is at fault
Title: Planck_constant
Context: The theoretical difficulties arise from the fact that all of the methods except the X-ray crystal density method rely on the theoretical basis of the Josephson effect and the quantum Hall effect. If these theories are slightly inaccurate – though there is no evidence at present to suggest they are – the methods would not give accurate values for the Planck constant. More importantly, the values of the Planck constant obtained in this way cannot be used as tests of the theories without falling into a circular argument. Fortunately, there are other statistical ways of testing the theories, and the theories have yet to be refuted.

question: Other than the X-ray crystal density method, other methods rely on what two effects? 

answer: the Josephson effect and the quantum Hall effect

question: Why does relying on these effects create concern? 

answer: If these theories are slightly inaccurate

question: Using Planck constant values from these effects would lead to what logical issue? 

answer: a circular argument

question: What is the saving grace of relying on these theories? 

answer: there are other statistical ways of testing the theories, and the theories have yet to be refuted.
Title: Planck_constant
Context: A watt balance is an instrument for comparing two powers, one of which is measured in SI watts and the other of which is measured in conventional electrical units. From the definition of the conventional watt W90, this gives a measure of the product KJ2RK in SI units, where RK is the von Klitzing constant which appears in the quantum Hall effect. If the theoretical treatments of the Josephson effect and the quantum Hall effect are valid, and in particular assuming that RK = h/e2, the measurement of KJ2RK is a direct determination of the Planck constant.

question: What is a watt balance? 

answer: an instrument for comparing two powers, one of which is measured in SI watts and the other of which is measured in conventional electrical units

question: What value does RK represent? 

answer: the von Klitzing constant which appears in the quantum Hall effect

question: If the effects are valid, for RK = n/e2, what is the measurement of KJ2RK equal to? 

answer: the Planck constant
Title: Planck_constant
Context: The gyromagnetic ratio γ is the constant of proportionality between the frequency ν of nuclear magnetic resonance (or electron paramagnetic resonance for electrons) and the applied magnetic field B: ν = γB. It is difficult to measure gyromagnetic ratios precisely because of the difficulties in precisely measuring B, but the value for protons in water at 7002298150000000000♠25 °C is known to better than one part per million. The protons are said to be "shielded" from the applied magnetic field by the electrons in the water molecule, the same effect that gives rise to chemical shift in NMR spectroscopy, and this is indicated by a prime on the symbol for the gyromagnetic ratio, γ′p. The gyromagnetic ratio is related to the shielded proton magnetic moment μ′p, the spin number I (I = 1⁄2 for protons) and the reduced Planck constant.

question: The gyromagnetic ratio is the constant proportion between the magentic field and what? 

answer: the frequency ν of nuclear magnetic resonance

question: How does the water molecule impact the effect of magnetic fields on protons? 

answer: The protons are said to be "shielded" from the applied magnetic field by the electrons in the water molecule

question: What three factors impact the gyromagnetic ratio? 

answer: related to the shielded proton magnetic moment μ′p, the spin number I (I = 1⁄2 for protons) and the reduced Planck constant.

question: The gyromagnetic ratio is often difficult to determine due to difficulty accurately determining the value of what? 

answer: the applied magnetic field B
Title: Planck_constant
Context: A further complication is that the measurement of γ′p involves the measurement of an electric current: this is invariably measured in conventional amperes rather than in SI amperes, so a conversion factor is required. The symbol Γ′p-90 is used for the measured gyromagnetic ratio using conventional electrical units. In addition, there are two methods of measuring the value, a "low-field" method and a "high-field" method, and the conversion factors are different in the two cases. Only the high-field value Γ′p-90(hi) is of interest in determining the Planck constant.

question: How many methods of measuring the gyromagnetic ratio are there? 

answer: there are two methods of measuring the value

question: How do conversion factors compare in "low-field" and "high-field" methods of measuring the gyromagnetic ratio? 

answer: the conversion factors are different in the two cases

question: Which method is of interest in determining the Planck constant? 

answer: Only the high-field value Γ′p-90(hi) is of interest in determining the Planck constant

question: Why is the measurement of electric current an issue in the estimate of the gyromagnetic ratio? 

answer: electric current: this is invariably measured in conventional amperes rather than in SI amperes
Title: Planck_constant
Context: The Faraday constant F is the charge of one mole of electrons, equal to the Avogadro constant NA multiplied by the elementary charge e. It can be determined by careful electrolysis experiments, measuring the amount of silver dissolved from an electrode in a given time and for a given electric current. In practice, it is measured in conventional electrical units, and so given the symbol F90. Substituting the definitions of NA and e, and converting from conventional electrical units to SI units, gives the relation to the Planck constant.

question: What is the Faraday constant? 

answer: the charge of one mole of electrons

question: How is the Faraday constant determined? 

answer: by careful electrolysis experiments, measuring the amount of silver dissolved from an electrode in a given time and for a given electric current.

question: How does the Faraday constant relate to the Planck constant? 

answer: Substituting the definitions of NA and e, and converting from conventional electrical units to SI units, gives the relation to the Planck constant.

question: How is the Farday constant value quickly calculated? 

answer: the Avogadro constant NA multiplied by the elementary charge e
Title: Planck_constant
Context: The X-ray crystal density method is primarily a method for determining the Avogadro constant NA but as the Avogadro constant is related to the Planck constant it also determines a value for h. The principle behind the method is to determine NA as the ratio between the volume of the unit cell of a crystal, measured by X-ray crystallography, and the molar volume of the substance. Crystals of silicon are used, as they are available in high quality and purity by the technology developed for the semiconductor industry. The unit cell volume is calculated from the spacing between two crystal planes referred to as d220. The molar volume Vm(Si) requires a knowledge of the density of the crystal and the atomic weight of the silicon used. The Planck constant is given by

question: What is the primary method for determining the Avogadro constant? 

answer: The X-ray crystal density method

question: The Avogadro constant is determined to be the ratio between what two factors in the X-ray crystal density method? 

answer: the volume of the unit cell of a crystal, measured by X-ray crystallography, and the molar volume of the substance

question: What element is used typically to establish Avogadro's constant? 

answer: Crystals of silicon

question: How is unit cell volume calculated? 

answer: from the spacing between two crystal planes referred to as d220

question: Calculating molar volume requires knowledge of what two factors? 

answer: the density of the crystal and the atomic weight of the silicon used
Title: Planck_constant
Context: There are a number of proposals to redefine certain of the SI base units in terms of fundamental physical constants. This has already been done for the metre, which is defined in terms of a fixed value of the speed of light. The most urgent unit on the list for redefinition is the kilogram, whose value has been fixed for all science (since 1889) by the mass of a small cylinder of platinum–iridium alloy kept in a vault just outside Paris. While nobody knows if the mass of the International Prototype Kilogram has changed since 1889 – the value 1 kg of its mass expressed in kilograms is by definition unchanged and therein lies one of the problems – it is known that over such a timescale the many similar Pt–Ir alloy cylinders kept in national laboratories around the world, have changed their relative mass by several tens of parts per million, however carefully they are stored, and the more so the more they have been taken out and used as mass standards. A change of several tens of micrograms in one kilogram is equivalent to the current uncertainty in the value of the Planck constant in SI units.

question: What measurement is deemed most important to redefine in terms of physical constants? 

answer: the kilogram

question: What is the shape of the object that establishes the base unit of the kilogram? 

answer: cylinder

question: What alloy is the base unit of the kilogram made from? 

answer: platinum–iridium

question: Where is the base unit for the kilogram kept? 

answer: in a vault just outside Paris
Title: Planck_constant
Context: The legal process to change the definition of the kilogram is already underway, but it had been decided that no final decision would be made before the next meeting of the General Conference on Weights and Measures in 2011. (For more detailed information, see kilogram definitions.) The Planck constant is a leading contender to form the basis of the new definition, although not the only one. Possible new definitions include "the mass of a body at rest whose equivalent energy equals the energy of photons whose frequencies sum to 7050135639273999999♠135639274×1042 Hz", or simply "the kilogram is defined so that the Planck constant equals 6966662606895999999♠6.62606896×10−34 J⋅s".

question: Where would the decision to change the definition of the kilogram have occured at the earliest? 

answer: the General Conference on Weights and Measures in 2011

question: Was the Planck constant the only option for redefining the kilogram? 

answer: The Planck constant is a leading contender to form the basis of the new definition, although not the only one

question: The mass of a resting body with what energy would be equal to a kilogram? 

answer: 7050135639273999999♠135639274×1042 Hz

question: A kilogram could be definined as having a Planck constant of what value? 

answer: 6966662606895999999♠6.62606896×10−34 J⋅s
Title: Comcast
Context: Comcast Corporation, formerly registered as Comcast Holdings,[note 1] is an American multinational mass media company and is the largest broadcasting and largest cable company in the world by revenue. It is the second largest pay-TV company after the AT&T-DirecTV acquisition, largest cable TV company and largest home Internet service provider in the United States, and the nation's third largest home telephone service provider. Comcast services U.S. residential and commercial customers in 40 states and the District of Columbia. The company's headquarters are located in Philadelphia, Pennsylvania.

question: What is the largest cable company in the world by revenue? 

answer: Comcast Corporation

question: What merged companies are the largest pay TV entity in the world? 

answer: AT&T-DirecTV

question: Comcast is also the largest media company in the United States in what broadband area? 

answer: Internet service provider

question: In what areas of the US does Comcast operate? 

answer: 40 states and the District of Columbia

question: Where is Comcast company headquarters? 

answer: Philadelphia, Pennsylvania
Title: Comcast
Context: Comcast operates multiple cable-only channels (including E! Entertainment Television, the Golf Channel, and NBCSN), over-the-air national broadcast network channels (NBC and Telemundo), the film production studio Universal Pictures, and Universal Parks & Resorts, with a global total of nearly 200 family entertainment locations and attractions in the U.S. and several other countries including U.A.E., South Korea, Russia and China, with several new locations reportedly planned and being developed for future operation. Comcast also has significant holding in digital distribution (thePlatform). In February 2014 the company agreed to merge with Time Warner Cable in an equity swap deal worth $45.2 billion. Under the terms of the agreement Comcast was to acquire 100% of Time Warner Cable. However, on April 24, 2015, Comcast terminated the agreement.

question: What are some of the cable TV networks owned by Comcast? 

answer: E! Entertainment Television, the Golf Channel, and NBCSN

question: What two national over-the-air broadcast entities are owned by Comcast? 

answer: NBC and Telemundo

question: Comcast owns what movie studio? 

answer: Universal Pictures

question: What company did Comcast propose a merger with? 

answer: Time Warner Cable

question: What date did Comcast drop their proposed merger agreement with Time Warner? 

answer: April 24, 2015
Title: Comcast
Context: Comcast has been criticized for multiple reasons. The company's customer satisfaction often ranks among the lowest in the cable industry. Comcast has violated net neutrality practices in the past; and, despite Comcast's commitment to a narrow definition of net neutrality, critics advocate a definition of which precludes distinction between Comcast's private network services and the rest of the Internet. Critics also point out a lack of competition in the vast majority of Comcast's service area; there is limited competition among cable providers. Given Comcast's negotiating power as a large ISP, some suspect that Comcast could leverage paid peering agreements to unfairly influence end-user connection speeds. Its ownership of both content production (in NBCUniversal) and content distribution (as an ISP) has raised antitrust concerns. These issues, in addition to others, led to Comcast being dubbed "The Worst Company in America" by The Consumerist in 2014 and 2010.

question: What is the largest criticism leveled by consumers against Comcast 

answer: customer satisfaction

question: It has been alleged that Comcast's internet service has done what to customers?  

answer: has violated net neutrality practices

question: What monopolistic practice draws criticism of Comcast? 

answer: a lack of competition in the vast majority of Comcast's service area

question: What dubious distinction has Comcast earned twice from The Consumerist? 

answer: "The Worst Company in America"

question: How does Comcast's customer service stack up against its competition? 

answer: often ranks among the lowest in the cable industry
Title: Comcast
Context: Comcast is sometimes described as a family business. Brian L. Roberts, Chairman, President, and CEO of Comcast, is son of co-founder Ralph Roberts. Roberts owns or controls just over 1% of all Comcast shares but all of the Class B supervoting shares, which gives him an "undilutable 33% voting power over the company". Legal expert Susan P. Crawford has said this gives him "effective control over its [Comcast's] every step". In 2010, he was one of the highest-paid executives in the United States, with total compensation of about $31 million.

question: Who is the current head of Comcast? 

answer: Brian L. Roberts

question: Who co-founded Comcast? 

answer: Ralph Roberts

question: In what year was Roberts ranked as the country's highest-paid executive? 

answer: 2010

question: What was Roberts' yearly salary in that year? 

answer: about $31 million

question: What is Roberts power on the Comcast board? 

answer: "undilutable 33% voting power over the company"
Title: Comcast
Context: The company is often criticized by both the media and its own staff for its less upstanding policies regarding employee relations. A 2012 Reddit post written by an anonymous Comcast call center employee eager to share their negative experiences with the public received attention from publications including The Huffington Post. A 2014 investigative series published by The Verge involved interviews with 150 of Comcast's employees. It sought to examine why the company has become so widely criticized by its customers, the media and even members of its own staff. The series claimed part of the problem is internal and that Comcast's staff endures unreasonable corporate policies. According to the report: "customer service has been replaced by an obsession with sales; technicians are understaffed while tech support is poorly trained; and the company is hobbled by internal fragmentation." A widely read article penned by an anonymous call center employee working for Comcast appeared in November 2014 on Cracked. Titled "Five Nightmares You Live While Working For America's Worst Company," the article also claimed that Comcast is obsessed with sales, doesn't train its employees properly and concluded that "the system makes good customer service impossible."

question: Besides customer problems, what other area is Comcast often criticized over? 

answer: employee relations

question: What online media outlet ran an investigative series on Comcast in 2014? 

answer: The Verge

question: How many Comcast employees were interviewed for that investigative report? 

answer: 150

question: What online publication ran a feature from a Comcast employee in 2014 that received attention? 

answer: Cracked

question: What was this 2014 article anonymously penned by a Comcast Employee called? 

answer: "Five Nightmares You Live While Working For America's Worst Company,"
Title: Comcast
Context: Comcast has also earned a reputation for being anti-union. According to one of the company's training manuals, "Comcast does not feel union representation is in the best interest of its employees, customers, or shareholders". A dispute in 2004 with CWA, a labor union that represented many employees at Comcast's offices in Beaverton, Oregon, led to allegations of management intimidating workers, requiring them to attend anti-union meetings and unwarranted disciplinary action for union members. In 2011, Comcast received criticism from Writers Guild of America for its policies in regards to unions.

question: What is Comcast's stance on organized labor? 

answer: anti-union

question: A 2004 labor dispute in what city highlighted Comcast's anti-labor stance? 

answer: Beaverton, Oregon

question: What was one anti-union thing that workers in Beaverton were required to do? 

answer: attend anti-union meetings

question: What creative union aired grievances against Comcast in 2011? 

answer: Writers Guild of America

question: In what internal publication was Comcast's union stance formally enumerated? 

answer: one of the company's training manuals
Title: Comcast
Context: Despite these criticisms, Comcast has appeared on multiple "top places to work" lists. In 2009, it was included on CableFAX magazine's "Top 10 Places to Work in Cable", which cited its "scale, savvy and vision". Similarly, the Philadelphia Business Journal awarded Comcast the silver medal among extra-large companies in Philadelphia, with the gold medal going to partner organization, Comcast-Spectacor. The Boston Globe found Comcast to be that city's top place to work in 2009. Employee diversity is also an attribute upon which Comcast receives strong marks. In 2008, Black Enterprise magazine rated Comcast among the top 15 companies for workforce diversity. Comcast was also named a "Top 2014 Workplace" by the Washington Post in their annual feature.

question: What magazine listed Comcast as one of its top places to work? 

answer: CableFAX

question: What is Comcast's affiliated entity in Philadelphia? 

answer: Comcast-Spectacor

question: What newspaper named Comcast it's top place to work? 

answer: The Boston Globe

question: In what year did this newspaper confer this honor on Comcast? 

answer: 2009

question: On what aspect did Black Enterprise Magazine name Comcast a top 15 employer? 

answer: workforce diversity
Title: Comcast
Context: The book value of the company nearly doubled from $8.19 a share in 1999 to $15 a share in 2009. Revenues grew sixfold from 1999's $6 billion to almost $36 billion in 2009. Net profit margin rose from 4.2% in 1999 to 8.4% in 2009, with operating margins improving 31 percent and return on equity doubling to 6.7 percent in the same time span. Between 1999 and 2009, return on capital nearly tripled to 7 percent. Comcast reported first quarter 2012 profit increases of 30% due to increase in high-speed internet customers. In February 2014, Comcast generated 1.1 billion in revenue during the first quarter due to the Sochi Olympics,.

question: What was Comcast's share value in 1999? 

answer: $8.19

question: What was Comcast's share value in 2009? 

answer: $15

question: Comcast's revenues in 2009 were how much? 

answer: $36 billion

question: What was Comcast's profit margin in 2009? 

answer: 8.4%

question: What caused a 2012 spike in Comcast profits? 

answer: increase in high-speed internet customers