Question: The continuous torque density of conventional electric machines is determined by the size of the air-gap area and the back-iron depth, which are determined by the power rating of the armature winding set, the speed of the machine, and the achievable air-gap flux density before core saturation. Despite the high coercivity of neodymium or samarium-cobalt PMs, continuous torque density is virtually the same amongst electric machines with optimally designed armature winding sets. Continuous torque density relates to method of cooling and permissible period of operation before destruction by overheating of windings or PM damage.
Try to answer this question if possible: What doesn't continuous torque density refer to?
Answer: unanswerable
Question: Chapter IV details natural selection under the "infinitely complex and close-fitting ... mutual relations of all organic beings to each other and to their physical conditions of life". Darwin takes as an example a country where a change in conditions led to extinction of some species, immigration of others and, where suitable variations occurred, descendants of some species became adapted to new conditions. He remarks that the artificial selection practised by animal breeders frequently produced sharp divergence in character between breeds, and suggests that natural selection might do the same, saying:
Try to answer this question if possible: What can happen if species immigrate to a new location?
Answer: descendants of some species became adapted to new conditions
Question: In the Late Empire and Middle Ages Vergilius was spelled Virgilius. Two explanations are commonly given for this alteration. One deduces a false etymology associated with the word virgo ("maiden" in Latin) due to Virgil's excessive, "maiden"-like modesty. Alternatively, some argue that Vergilius was altered to Virgilius by analogy with the Latin virga ("wand") due to the magical or prophetic powers attributed to Virgil in the Middle Ages (this explanation is found in only a handful of manuscripts, however, and was probably not widespread). In Norman schools (following the French practice), the habit was to anglicize Latin names by dropping their Latin endings, hence Virgil. In the 19th century, some German-trained classicists in the United States suggested modification to Vergil, as it is closer to his original name, and is also the traditional German spelling.[citation needed] Modern usage permits both, though the Oxford guide to style recommends Vergilius to avoid confusion with the 8th-century grammarian Virgilius Maro Grammaticus. Some post-Renaissance writers liked to affect the sobriquet "The Swan of Mantua".[citation needed]
Try to answer this question if possible: Who attributed magical powers to Virgil in the middle ages?
Answer: unanswerable
Question: At the time the store was introduced, purchased audio files used the AAC format with added encryption, based on the FairPlay DRM system. Up to five authorized computers and an unlimited number of iPods could play the files. Burning the files with iTunes as an audio CD, then re-importing would create music files without the DRM. The DRM could also be removed using third-party software. However, in a deal with Apple, EMI began selling DRM-free, higher-quality songs on the iTunes Stores, in a category called "iTunes Plus." While individual songs were made available at a cost of US$1.29, 30 more than the cost of a regular DRM song, entire albums were available for the same price, US$9.99, as DRM encoded albums. On October 17, 2007, Apple lowered the cost of individual iTunes Plus songs to US$0.99 per song, the same as DRM encoded tracks. On January 6, 2009, Apple announced that DRM has been removed from 80% of the music catalog, and that it would be removed from all music by April 2009.
Try to answer this question if possible: In what year was DRM completely eliminated from the iTunes offerings?
Answer:
2009