Problem: Electrolytic capacitors use an aluminum or tantalum plate with an oxide dielectric layer. The second electrode is a liquid electrolyte, connected to the circuit by another foil plate. Electrolytic capacitors offer very high capacitance but suffer from poor tolerances, high instability, gradual loss of capacitance especially when subjected to heat, and high leakage current. Poor quality capacitors may leak electrolyte, which is harmful to printed circuit boards. The conductivity of the electrolyte drops at low temperatures, which increases equivalent series resistance. While widely used for power-supply conditioning, poor high-frequency characteristics make them unsuitable for many applications. Electrolytic capacitors will self-degrade if unused for a period (around a year), and when full power is applied may short circuit, permanently damaging the capacitor and usually blowing a fuse or causing failure of rectifier diodes (for instance, in older equipment, arcing in rectifier tubes). They can be restored before use (and damage) by gradually applying the operating voltage, often done on antique vacuum tube equipment over a period of 30 minutes by using a variable transformer to supply AC power. Unfortunately, the use of this technique may be less satisfactory for some solid state equipment, which may be damaged by operation below its normal power range, requiring that the power supply first be isolated from the consuming circuits. Such remedies may not be applicable to modern high-frequency power supplies as these produce full output voltage even with reduced input.
What type of dielectric layer is never used in electrolytic capacitors?
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Answer: unanswerable

Problem: The monogram theme was developed into an Art Deco-style badge on which the letters A and C framed a football rather than the letter F, the whole set within a hexagonal border. This early example of a corporate logo, introduced as part of Herbert Chapman's rebranding of the club in the 1930s, was used not only on Cup Final shirts but as a design feature throughout Highbury Stadium, including above the main entrance and inlaid in the floors. From 1967, a white cannon was regularly worn on the shirts, until replaced by the club crest, sometimes with the addition of the nickname "The Gunners", in the 1990s.
What was worn on Arsenal shirts prior to 1967?
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Answer: unanswerable

Problem: The years following 2009 marked a shift in the structure of the "Big Four" with Tottenham Hotspur and Manchester City both breaking into the top four. In the 200910 season, Tottenham finished fourth and became the first team to break the top four since Everton in 2005. Criticism of the gap between an elite group of "super clubs" and the majority of the Premier League has continued, nevertheless, due to their increasing ability to spend more than the other Premier League clubs. Manchester City won the title in the 201112 season, becoming the first club outside the "Big Four" to win since 199495. That season also saw two of the Big Four (Chelsea and Liverpool) finish outside the top four places for the first time since 199495.
During which season did Tottenham become the second team to enter the top four since 2005?
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Answer:
unanswerable