Problem: The majority of antenna designs are based on the resonance principle. This relies on the behaviour of moving electrons, which reflect off surfaces where the dielectric constant changes, in a fashion similar to the way light reflects when optical properties change. In these designs, the reflective surface is created by the end of a conductor, normally a thin metal wire or rod, which in the simplest case has a feed point at one end where it is connected to a transmission line. The conductor, or element, is aligned with the electrical field of the desired signal, normally meaning it is perpendicular to the line from the antenna to the source (or receiver in the case of a broadcast antenna).
What type of surface is formed by the tip of a conductor?
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Answer: reflective


Problem: In absolute terms, the planet has lost 52% of its biodiversity since 1970 according to a 2014 study by the World Wildlife Fund. The Living Planet Report 2014 claims that "the number of mammals, birds, reptiles, amphibians and fish across the globe is, on average, about half the size it was 40 years ago". Of that number, 39% accounts for the terrestrial wildlife gone, 39% for the marine wildlife gone, and 76% for the freshwater wildlife gone. Biodiversity took the biggest hit in Latin America, plummeting 83 percent. High-income countries showed a 10% increase in biodiversity, which was canceled out by a loss in low-income countries. This is despite the fact that high-income countries use five times the ecological resources of low-income countries, which was explained as a result of process whereby wealthy nations are outsourcing resource depletion to poorer nations, which are suffering the greatest ecosystem losses.
What percentage accounts for the wealthy nations gone?
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Answer: unanswerable


Problem: In September 2012 at the Tokyo Game Show, Sony announced that a new, slimmer PS3 redesign (CECH-4000) was due for release in late 2012 and that it would be available with either a 250 GB or 500 GB hard drive. Three versions Super Slim model were revealed: one with a 500 GB hard drive, a second with a 250 GB hard drive which is not available in PAL regions, and a third with a 12 GB flash storage that was only available in PAL regions. The storage of 12 GB model is upgradable with an official standalone 250 GB hard drive. A vertical stand was also released for the model. In the United Kingdom, the 500 GB model was released on September 28, 2012; and the 12 GB model was released on October 12, 2012. In the United States, the PS3 Super Slim was first released as a bundled console. The 250 GB was model was bundled with Game of the Year edition of Uncharted 3: Drake's Deception and released on September 25, 2012; and the 500 GB model was bundled with Assassin's Creed III and released on October 30, 2012. In Japan, the black colored Super Slim model was released on October 4, 2012; and the white colored Super Slim model was released on November 22, 2012. The Super Slim model is 20 percent smaller and 25 percent lighter than the Slim model and features a manual sliding disc cover instead of a motorized slot-loading disc cover of the Slim model. The white colored Super Slim model was released in the United States on January 27, 2013 as part of the Instant Game Collection Bundle. The Garnet Red and Azurite Blue colored models were launched in Japan on February 28, 2013. The Garnet Red version was released in North America on March 12, 2013 as part of the God of War: Ascension bundle with 500 GB storage and contained God of War: Ascension as well as the God of War Saga. The Azurite Blue model was released as a GameStop exclusive with 250GB storage.
How many versions of the CECH-4000 weren't made?
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Answer:
unanswerable