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

Problem: Tajikistan is officially a republic, and holds elections for the presidency and parliament, operating under a presidential system. It is, however, a dominant-party system, where the People's Democratic Party of Tajikistan routinely has a vast majority in Parliament. Emomalii Rahmon has held the office of President of Tajikistan continually since November 1994. The Prime Minister is Kokhir Rasulzoda, the First Deputy Prime Minister is Matlubkhon Davlatov and the two Deputy Prime Ministers are Murodali Alimardon and Ruqiya Qurbanova.
Who are the Deputy Prime Ministers?
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Answer: Murodali Alimardon and Ruqiya Qurbanova

Problem: To create green sparks, fireworks use barium salts, such as barium chlorate, barium nitrate crystals, or barium chloride, also used for green fireplace logs. Copper salts typically burn blue, but cupric chloride (also known as "campfire blue") can also produce green flames. Green pyrotechnic flares can use a mix ratio 75:25 of boron and potassium nitrate. Smoke can be turned green by a mixture: solvent yellow 33, solvent green 3, lactose, magnesium carbonate plus sodium carbonate added to potassium chlorate.
What type of copper salts are used in fireworks?
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Answer:
unanswerable