nc33/MultiSpan_SQUAD huggingface dataset:
Incandescent_light_bulb

In a conventional lamp, the evaporated tungsten eventually condenses on the inner surface of the glass envelope, darkening it. For bulbs that contain a vacuum, the darkening is uniform across the entire surface of the envelope. When a filling of inert gas is used, the evaporated tungsten is carried in the thermal convection currents of the gas, depositing preferentially on the uppermost part of the envelope and blackening just that portion of the envelope. An incandescent lamp that gives 93% or less of its initial light output at 75% of its rated life is regarded as unsatisfactory, when tested according to IEC Publication 60064. Light loss is due to filament evaporation and bulb blackening. Study of the problem of bulb blackening led to the discovery of the Edison effect, thermionic emission and invention of the vacuum tube.

Question: What darkens a conventional bulb over its lifetime?
Answer: the evaporated tungsten eventually condenses on the inner surface of the glass envelope

Question: What is the IEC guideline for an unacceptable level of light loss?
Answer: An incandescent lamp that gives 93% or less of its initial light output at 75% of its rated life is regarded as unsatisfactory

Question: What are the primary causes of light loss?
Answer: Light loss is due to filament evaporation and bulb blackening

Question: Where in the bulb is evaporated tungsten deposited when inert gas is used?
Answer: on the uppermost part of the envelope

Question: Where in the bulb is evaporated tungsten deposited when a vacuum is used?
Answer: across the entire surface of the envelope
Incandescent_light_bulb

A very small amount of water vapor inside a light bulb can significantly affect lamp darkening. Water vapor dissociates into hydrogen and oxygen at the hot filament. The oxygen attacks the tungsten metal, and the resulting tungsten oxide particles travel to cooler parts of the lamp. Hydrogen from water vapor reduces the oxide, reforming water vapor and continuing this water cycle. The equivalent of a drop of water distributed over 500,000 lamps will significantly increase darkening. Small amounts of substances such as zirconium are placed within the lamp as a getter to react with any oxygen that may bake out of the lamp components during operation.

Question: How does water vapor inside a light bulb affect lamp darkening?
Answer: significantly increase darkening

Question: Why does water increase lamp darkening?
Answer: The oxygen attacks the tungsten metal, and the resulting tungsten oxide particles travel to cooler parts of the lamp.

Question: What is an example of a substance that is added to light bulbs to reduce this effect?
Answer: zirconium

Question: How much water is necessary to result in this darkening affect?
Answer: The equivalent of a drop of water distributed over 500,000 lamps
Incandescent_light_bulb

The halogen lamp reduces uneven evaporation of the filament and eliminates darkening of the envelope by filling the lamp with a halogen gas at low pressure, rather than an inert gas. The halogen cycle increases the lifetime of the bulb and prevents its darkening by redepositing tungsten from the inside of the bulb back onto the filament. The halogen lamp can operate its filament at a higher temperature than a standard gas filled lamp of similar power without loss of operating life. Such bulbs are much smaller than normal incandescent bulbs, and are widely used where intense illumination is needed in a limited space. Fiber-optic lamps for optical microscopy is one typical application.

Question: Does the halogen bulp increase, reduce, or have no effect on filament evaporation?
Answer: reduces

Question: How does the halogen bulb decrease darkening over time?
Answer: by redepositing tungsten from the inside of the bulb back onto the filament

Question: Does a halogen bulb operate at a higher or lower temperature than an incandescent?
Answer: higher

Question: How does the size of a halogen bulb compare to an incandescent?
Answer: bulbs are much smaller than normal incandescent bulbs

Question: What is the most common situation when a halogen bulb is used?
Answer: where intense illumination is needed in a limited space
Incandescent_light_bulb

A variation of the incandescent lamp did not use a hot wire filament, but instead used an arc struck on a spherical bead electrode to produce heat. The electrode then became incandescent, with the arc contributing little to the light produced. Such lamps were used for projection or illumination for scientific instruments such as microscopes. These arc lamps ran on relatively low voltages and incorporated tungsten filaments to start ionization within the envelope. They provided the intense concentrated light of an arc lamp but were easier to operate. Developed around 1915, these lamps were displaced by mercury and xenon arc lamps.

Question: What did an alternate version of the incandescent lamp substitute for a wire filament?
Answer: an arc struck on a spherical bead electrode

Question: What was a common application for this type of bulb?
Answer: scientific instruments such as microscopes

Question: When was this style of lamp developed?
Answer: 1915

Question: What displaced this style of lamp?
Answer: mercury and xenon arc lamps
Incandescent_light_bulb

Incandescent lamps are nearly pure resistive loads with a power factor of 1. This means the actual power consumed (in watts) and the apparent power (in volt-amperes) are equal. Incandescent light bulbs are usually marketed according to the electrical power consumed. This is measured in watts and depends mainly on the resistance of the filament, which in turn depends mainly on the filament's length, thickness, and material. For two bulbs of the same voltage, type, color, and clarity, the higher-powered bulb gives more light.

Question: What does a power factor of 1 mean?
Answer: the actual power consumed (in watts) and the apparent power (in volt-amperes) are equal

Question: What principally determines the wattage of an incandescent bulb?
Answer: the resistance of the filament

Question: What determines the resistance of the filament?
Answer: the filament's length, thickness, and material

Question: How close do incandescent lamps come to pure resistive loads?
Answer: Incandescent lamps are nearly pure resistive loads

Question: All other things being equal, how does wattage affect light emitted?
Answer: the higher-powered bulb gives more light
Incandescent_light_bulb

The actual resistance of the filament is temperature dependent. The cold resistance of tungsten-filament lamps is about 1/15 the hot-filament resistance when the lamp is operating. For example, a 100-watt, 120-volt lamp has a resistance of 144 ohms when lit, but the cold resistance is much lower (about 9.5 ohms). Since incandescent lamps are resistive loads, simple phase-control TRIAC dimmers can be used to control brightness. Electrical contacts may carry a "T" rating symbol indicating that they are designed to control circuits with the high inrush current characteristic of tungsten lamps. For a 100-watt, 120-volt general-service lamp, the current stabilizes in about 0.10 seconds, and the lamp reaches 90% of its full brightness after about 0.13 seconds.

Question: What determines the resistance of a filament?
Answer: temperature

Question: What does a "T" rating symbol on an electrical contact mean?
Answer: they are designed to control circuits with the high inrush current characteristic of tungsten lamps

Question: How long does it take a typical 100-watt bulb to achieve 90% of its brightness?
Answer: 0.13 seconds

Question: How does the cold resistance of tungsten filament lamps compare to the hot resistance?
Answer: The cold resistance of tungsten-filament lamps is about 1/15 the hot-filament resistance

Question: What is the resistance of a typical lit 100-watt incandescent bulb?
Answer: 144 ohms
Incandescent_light_bulb

Incandescent light bulbs come in a range of shapes and sizes. The names of the shapes may be slightly different in some regions. Many of these shapes have a designation consisting of one or more letters followed by one or more numbers, e.g. A55 or PAR38. The letters represent the shape of the bulb. The numbers represent the maximum diameter, either in 1⁄8 of an inch, or in millimeters, depending on the shape and the region. For example, 63 mm reflectors are designated R63, but in the US, they are known as R20 (2.5 in). However, in both regions, a PAR38 reflector is known as PAR38.

Question: What do the letters identify in a bulb shape designation?
Answer: the shape of the bulb

Question: What do the numbers identify in a bulb shape designation?
Answer: the maximum diameter

Question: Can the name of a certain bulb shape vary?
Answer: The names of the shapes may be slightly different in some regions

Question: What units are the bulb sizes measured in?
Answer: 1⁄8 of an inch, or in millimeters
Incandescent_light_bulb

Very small lamps may have the filament support wires extended through the base of the lamp, and can be directly soldered to a printed circuit board for connections. Some reflector-type lamps include screw terminals for connection of wires. Most lamps have metal bases that fit in a socket to support the lamp and conduct current to the filament wires. In the late 19th century, manufacturers introduced a multitude of incompatible lamp bases. General Electric introduced standard base sizes for tungsten incandescent lamps under the Mazda trademark in 1909. This standard was soon adopted across the US, and the Mazda name was used by many manufacturers under license through 1945. Today most incandescent lamps for general lighting service use an Edison screw in candelabra, intermediate, or standard or mogul sizes, or double contact bayonet base. Technical standards for lamp bases include ANSI standard C81.67 and IEC standard 60061-1 for common commercial lamp sizes, to ensure interchangeablitity between different manufacturer's products. Bayonet base lamps are frequently used in automotive lamps to resist loosening due to vibration. A bipin base is often used for halogen or reflector lamps.

Question: Which company introduced standard base sizes for incandescent lamps?
Answer: General Electric

Question: In what year were standard base sizes introduced for incandescent lamps?
Answer: 1909

Question: What are some common technical standards for lamp bases?
Answer: ANSI standard C81.67 and IEC standard 60061-1

Question: What is the typical base type for automotive lamps?
Answer: Bayonet base lamps

Question: What is the typical base type for halogen lamps?
Answer: bipin base
Incandescent_light_bulb

This means that a 5% reduction in operating voltage will more than double the life of the bulb, at the expense of reducing its light output by about 16%. This may be a very acceptable trade off for a light bulb that is in a difficult-to-access location (for example, traffic lights or fixtures hung from high ceilings). Long-life bulbs take advantage of this trade-off. Since the value of the electric power they consume is much more than the value of the lamp, general service lamps emphasize efficiency over long operating life. The objective is to minimize the cost of light, not the cost of lamps. Early bulbs had a life of up to 2500 hours, but in 1924 a cartel agreed to limit life to 1000 hours. When this was exposed in 1953, General Electric and other leading American manufacturers were banned from limiting the life.

Question: What level of voltage reduction is required to double the life of an incandescent bulb?
Answer: a 5% reduction in operating voltage

Question: When did light bulb manufacturers establish a cartel to limit bulb life?
Answer: 1924

Question: When did authorities break up the light bulb cartel?
Answer: 1953

Question: What was the artificially low limit on bulb life placed by the cartel?
Answer: 1000 hours

Question: What is an example of a good application for a long-life bulb?
Answer: difficult-to-access location (for example, traffic lights or fixtures hung from high ceilings)
Incandescent_light_bulb

The relationships above are valid for only a few percent change of voltage around rated conditions, but they do indicate that a lamp operated at much lower than rated voltage could last for hundreds of times longer than at rated conditions, albeit with greatly reduced light output. The "Centennial Light" is a light bulb that is accepted by the Guinness Book of World Records as having been burning almost continuously at a fire station in Livermore, California, since 1901. However, the bulb emits the equivalent light of a four watt bulb. A similar story can be told of a 40-watt bulb in Texas that has been illuminated since 21 September 1908. It once resided in an opera house where notable celebrities stopped to take in its glow, and was moved to an area museum in 1977.

Question: When did the "Centennial Light" begin burning?
Answer: 1901

Question: How much light does the bulb emit?
Answer: the equivalent light of a four watt bulb

Question: When did the long-lasting bulb in Texas begin continuing illumination?
Answer: 21 September 1908

Question: Where did the Texas bulb begin its life?
Answer: an opera house
Incandescent_light_bulb

In flood lamps used for photographic lighting, the tradeoff is made in the other direction. Compared to general-service bulbs, for the same power, these bulbs produce far more light, and (more importantly) light at a higher color temperature, at the expense of greatly reduced life (which may be as short as two hours for a type P1 lamp). The upper temperature limit for the filament is the melting point of the metal. Tungsten is the metal with the highest melting point, 3,695 K (6,191 °F). A 50-hour-life projection bulb, for instance, is designed to operate only 50 °C (122 °F) below that melting point. Such a lamp may achieve up to 22 lumens per watt, compared with 17.5 for a 750-hour general service lamp.

Question: At what temperature does a typical 50-hour-life projection bulb operate?
Answer: 50 °C (122 °F)

Question: Which metal has the highest melting point?
Answer: Tungsten

Question: What is the typical life of a P1 lamp?
Answer: as short as two hours

Question: How does the color temperature differ for photographic lighting?
Answer: higher color temperature
Incandescent_light_bulb

Lamps designed for different voltages have different luminous efficacy. For example, a 100-watt, 120-volt lamp will produce about 17.1 lumens per watt. A lamp with the same rated lifetime but designed for 230 V would produce only around 12.8 lumens per watt, and a similar lamp designed for 30 volts (train lighting) would produce as much as 19.8 lumens per watt. Lower voltage lamps have a thicker filament, for the same power rating. They can run hotter for the same lifetime before the filament evaporates.

Question: How many lumens per watt does a typical 100-watt, 120-volt lamp produce?
Answer: 17.1 lumens per watt

Question: How many lumens per watt does a typical train light produce?
Answer: as much as 19.8 lumens per watt

Question: How does filament size relate to voltage level?
Answer: Lower voltage lamps have a thicker filament

Question: What is the effect of a thicker filament on bulb temperature?
Answer: They can run hotter for the same lifetime before the filament evaporates.
Incandescent_light_bulb

In addressing the question of who invented the incandescent lamp, historians Robert Friedel and Paul Israel list 22 inventors of incandescent lamps prior to Joseph Swan and Thomas Edison. They conclude that Edison's version was able to outstrip the others because of a combination of three factors: an effective incandescent material, a higher vacuum than others were able to achieve (by use of the Sprengel pump) and a high resistance that made power distribution from a centralized source economically viable.

Question: What made power distribution economically viable in Edison's lamp?
Answer: high resistance

Question: How many inventors came up with electric lamps before Thomas Edison?
Answer: 22

Question: How did Edison achieve a higher vacuum than other inventors?
Answer: by use of the Sprengel pump

Question: Which historians wrote about the advantages of Edison's lamp over other early versions?
Answer: Robert Friedel and Paul Israel
Chicago_Cubs

In 1902, Spalding, who by this time had revamped the roster to boast what would soon be one of the best teams of the early century, sold the club to Jim Hart. The franchise was nicknamed the Cubs by the Chicago Daily News in 1902, although not officially becoming the Chicago Cubs until the 1907 season. During this period, which has become known as baseball's dead-ball era, Cub infielders Joe Tinker, Johnny Evers, and Frank Chance were made famous as a double-play combination by Franklin P. Adams' poem Baseball's Sad Lexicon. The poem first appeared in the July 18, 1910 edition of the New York Evening Mail. Mordecai "Three-Finger" Brown, Jack Taylor, Ed Reulbach, Jack Pfiester, and Orval Overall were several key pitchers for the Cubs during this time period. With Chance acting as player-manager from 1905 to 1912, the Cubs won four pennants and two World Series titles over a five-year span. Although they fell to the "Hitless Wonders" White Sox in the 1906 World Series, the Cubs recorded a record 116 victories and the best winning percentage (.763) in Major League history. With mostly the same roster, Chicago won back-to-back World Series championships in 1907 and 1908, becoming the first Major League club to play three times in the Fall Classic and the first to win it twice. However, the Cubs have not won a World Series since; this remains the longest championship drought in North American professional sports.

Question: Who did Spalding sell the Cubs to in 1902?
Answer: Jim Hart

Question: Who nicknamed the franchise the Cubs in 1902?
Answer: Chicago Daily News

Question: Who holds the longest championship drought in North American professional sports?
Answer: the Cubs

Question: Who wrote the poem Baseball's Sad Lexicon?
Answer: Franklin P. Adams
Chicago_Cubs

The Chicago Cubs have not won a World Series championship since 1908, and have not appeared in the Fall Classic since 1945, although between their postseason appearance in 1984 and their most recent in 2015, they have made the postseason seven times. 107 seasons is the longest championship drought in all four of the major North American professional sports leagues, which also includes the National Football League (NFL), the National Basketball Association (NBA), and the National Hockey League (NHL). In fact, the Cubs' last World Series title occurred before those other three leagues even existed, and even the Cubs' last World Series appearance predates the founding of the NBA. The much publicized drought was concurrent to championship droughts by the Boston Red Sox and the Chicago White Sox, who both had over 80 years between championships. It is this unfortunate distinction that has led to the club often being known as "The Lovable Losers." The team was one win away from breaking what is often called the "Curse of the Billy Goat" in 1984 and 2003 (Steve Bartman incident), but was unable get the victory that would send it to the World Series.

Question: What is the longest championship drought in all four of the major North American professional sports leagues?
Answer: 107 seasons

Question: The championship drought has led to the Chicago Cubs being know as what?
Answer: The Lovable Losers

Question: When was the last time the Chicago Cubs appeared in the Fall Classic?
Answer: 1945

Question: When was the last time the Chicago Cubs win a World Series championship?
Answer: 1908
States_of_Germany

Germany is a federal republic consisting of sixteen federal states (German: Bundesland, or Land).[a] Since today's Germany was formed from an earlier collection of several states, it has a federal constitution, and the constituent states retain a measure of sovereignty. With an emphasis on geographical conditions, Berlin and Hamburg are frequently called Stadtstaaten (city-states), as is the Free Hanseatic City of Bremen, which in fact includes the cities of Bremen and Bremerhaven. The remaining 13 states are called Flächenländer (literally: area states).

Question: How many federal states does Germany have?
Answer: sixteen

Question: What are Hamburg and Berlin called?
Answer: Stadtstaaten (city-states)

Question: The Free Hanseatic City of Bremen includes which two cities?
Answer: Bremen and Bremerhaven

Question: How many federal states does Germany have?
Answer: sixteen federal states

Question: What do constituent states still have?
Answer: measure of sovereignty

Question: What are the two major city-states?
Answer: Berlin and Hamburg

Question: What is the name of the city-state that contains Bremen and Bremerhaven?
Answer: Free Hanseatic City of Bremen

Question: What do Germans call the other 13 states?
Answer: Flächenländer

Question: How many states are in Germany?
Answer: sixteen

Question: Which cities are called Stadtstaaten, other than Bremen?
Answer: Berlin and Hamburg

Question: What is the German terms for states?
Answer: Bundesland, or Land

Question: How many states are called "Flächenländer"?
Answer: 13

Question: The Free Hanseatic City of Bremen includes which cities?
Answer: Bremen and Bremerhaven
States_of_Germany

The creation of the Federal Republic of Germany in 1949 was through the unification of the western states (which were previously under American, British, and French administration) created in the aftermath of World War II. Initially, in 1949, the states of the Federal Republic were Baden, Bavaria (in German: Bayern), Bremen, Hamburg, Hesse (Hessen), Lower Saxony (Niedersachsen), North Rhine Westphalia (Nordrhein-Westfalen), Rhineland-Palatinate (Rheinland-Pfalz), Schleswig-Holstein, Württemberg-Baden, and Württemberg-Hohenzollern. West Berlin, while officially not part of the Federal Republic, was largely integrated and considered as a de facto state.

Question: What year was the Federal Republic of Germany created?
Answer: 1949

Question: The Federal Republic of Germany was founded after which world war?
Answer: World War II

Question: What area was initially not apart of the Federal Republic of Germany?
Answer: West Berlin

Question: When was the Federal Republic of Germany formed?
Answer: 1949

Question: How did this republic come to be?
Answer: the aftermath of World War II

Question: How was the republic controlled at the end World War II?
Answer: American, British, and French administration

Question: Which state was NOT a part of the Federal Republic in 1949?
Answer: West Berlin

Question: When was the Federal Republic of Germany created
Answer: 1949

Question: Which countries administrations was the Federal Republic of Germany previously under?
Answer: American, British, and French

Question: Which city was originally not a part of the Federal Republic of Germany?
Answer: West Berlin

Question: What was the Federal Republic of Germany created in the aftermath of?
Answer: World War II