Problem: Incandescent light bulb:

The first successful light bulb filaments were made of carbon (from carbonized paper or bamboo). Early carbon filaments had a negative temperature coefficient of resistance — as they got hotter, their electrical resistance decreased. This made the lamp sensitive to fluctuations in the power supply, since a small increase of voltage would cause the filament to heat up, reducing its resistance and causing it to draw even more power and heat even further. In the "flashing" process, carbon filaments were heated by current passing through them while in an evacuated vessel containing hydrocarbon vapor (usually gasoline). The carbon deposited on the filament by this treatment improved the uniformity and strength of filaments as well as their efficiency. A metallized or "graphitized" filament was first heated in a high-temperature oven before flashing and lamp assembly. This transformed the carbon into graphite which further strengthened and smoothed the filament. This also changed the filament to have a positive temperature coefficient, like a metallic conductor, and helped stabilize the lamp's power consumption, temperature and light output against minor variations in supply voltage.

What are the effects of giving the filament a positive temperature coefficient?
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A: helped stabilize the lamp's power consumption, temperature and light output against minor variations in supply voltage


Problem: As anticipated by Nimitz, the Japanese fleet arrived off Midway on 4 June and was spotted by PBY patrol aircraft. Nagumo executed a first strike against Midway, while Fletcher launched his aircraft, bound for Nagumo's carriers. At 09:20 the first U.S. carrier aircraft arrived, TBD Devastator torpedo bombers from Hornet, but their attacks were poorly coordinated and ineffectual; thanks in part to faulty aerial torpedoes, they failed to score a single hit and all 15 were wiped out by defending Zero fighters. At 09:35, 15 additional TBDs from Enterprise attacked in which 14 were lost, again with no hits. Thus far, Fletcher's attacks had been disorganized and seemingly ineffectual, but they succeeded in drawing Nagumo's defensive fighters down to sea level where they expended much of their fuel and ammunition repulsing the two waves of torpedo bombers. As a result, when U.S. dive bombers arrived at high altitude, the Zeros were poorly positioned to defend. To make matters worse, Nagumo's four carriers had drifted out of formation in their efforts to avoid torpedoes, reducing the concentration of their anti-aircraft fire. Nagumo's indecision had also created confusion aboard his carriers. Alerted to the need of a second strike on Midway, but also wary of the need to deal with the American carriers that he now knew were in the vicinity, Nagumo twice changed the arming orders for his aircraft. As a result, the American dive bombers found the Japanese carriers with their decks cluttered with munitions as the crews worked hastily to properly re-arm their air groups.
When did the Japanese fleet arrive off Midway?
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Answer: 4 June


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
The Xbox 360 supports videos in Windows Media Video (WMV) format (including high-definition and PlaysForSure videos), as well as H.264 and MPEG-4 media. The December 2007 dashboard update added support for the playback of MPEG-4 ASP format videos. The console can also display pictures and perform slideshows of photo collections with various transition effects, and supports audio playback, with music player controls accessible through the Xbox 360 Guide button. Users may play back their own music while playing games or using the dashboard, and can play music with an interactive visual synthesizer.
How do gamers play videos while playing games?
A: unanswerable


Context and question: In 2005, the Office of Fair Trading found fifty independent schools, including Eton, to have breached the Competition Act by "regularly and systematically" exchanging information about planned increases in school fees, which was collated and distributed among the schools by the bursar at Sevenoaks School. Following the investigation by the OFT, each school was required to pay around £70,000, totalling around £3.5 million, significantly less than the maximum possible fine. In addition, the schools together agreed to contribute another £3m to a new charitable educational fund. The incident raised concerns over whether the charitable status of independent schools such as Eton should be reconsidered, and perhaps revoked. However, Jean Scott, the head of the Independent Schools Council, said that independent schools had always been exempt from anti-cartel rules applied to business, were following a long-established procedure in sharing the information with each other, and that they were unaware of the change to the law (on which they had not been consulted). She wrote to John Vickers, the OFT director-general, saying, "They are not a group of businessmen meeting behind closed doors to fix the price of their products to the disadvantage of the consumer. They are schools that have quite openly continued to follow a long-established practice because they were unaware that the law had changed."
Who defended fifty schools accused of price-sharing, stating they were unaware the laws had changed?
Answer: Jean Scott


Question: Many medieval philosophers developed arguments for the existence of God, while attempting to comprehend the precise implications of God's attributes. Reconciling some of those attributes generated important philosophical problems and debates. For example, God's omniscience may seem to imply that God knows how free agents will choose to act. If God does know this, their ostensible free will might be illusory, or foreknowledge does not imply predestination, and if God does not know it, God may not be omniscient.
Is there an answer to this question: What does it mean if God can't predict the future?

Answer: God may not be omniscient.


Problem: Dissolution of the Soviet Union:

The Alma-Ata Protocol also addressed other issues, including UN membership. Notably, Russia was authorized to assume the Soviet Union's UN membership, including its permanent seat on the Security Council. The Soviet Ambassador to the UN delivered a letter signed by Russian President Yeltsin to the UN Secretary-General dated December 24, 1991, informing him that by virtue of the Alma-Ata Protocol, Russia was the successor state to the USSR. After being circulated among the other UN member states, with no objection raised, the statement was declared accepted on the last day of the year, December 31, 1991.

When did the UN accept the statement?
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A:
December 31, 1991