Article: In 1824, the French physicist François Arago formulated the existence of rotating magnetic fields, termed Arago's rotations, which, by manually turning switches on and off, Walter Baily demonstrated in 1879 as in effect the first primitive induction motor.  In the 1880s, many inventors were trying to develop workable AC motors because AC's advantages in long-distance high-voltage transmission were counterbalanced by the inability to operate motors on AC. The first alternating-current commutatorless induction motors were independently invented by Galileo Ferraris and Nikola Tesla, a working motor model having been demonstrated by the former in 1885 and by the latter in 1887. In 1888, the Royal Academy of Science of Turin published Ferraris' research detailing the foundations of motor operation while however concluding that "the apparatus based on that principle could not be of any commercial importance as motor." In 1888, Tesla presented his paper A New System for Alternating Current Motors and Transformers to the AIEE that described three patented two-phase four-stator-pole motor types: one with a four-pole rotor forming a non-self-starting reluctance motor, another with a wound rotor forming a self-starting induction motor, and the third a true synchronous motor with separately excited DC supply to rotor winding. One of the patents Tesla filed in 1887, however, also described a shorted-winding-rotor induction motor. George Westinghouse promptly bought Tesla's patents, employed Tesla to develop them, and assigned C. F. Scott to help Tesla, Tesla left for other pursuits in 1889.  The constant speed AC induction motor was found not to be suitable for street cars but Westinghouse engineers successfully adapted it to power a mining operation in Telluride, Colorado in 1891. Steadfast in his promotion of three-phase development, Mikhail Dolivo-Dobrovolsky invented the three-phase cage-rotor induction motor in 1889 and the three-limb transformer in 1890. This type of motor is now used for the vast majority of commercial applications. However, he claimed that Tesla's motor was not practical because of two-phase pulsations, which prompted him to persist in his three-phase work. Although Westinghouse achieved its first practical induction motor in 1892 and developed a line of polyphase 60 hertz induction motors in 1893, these early Westinghouse motors were two-phase motors with wound rotors until B. G. Lamme developed a rotating bar winding rotor. The General Electric Company began developing three-phase induction motors in 1891. By 1896, General Electric and Westinghouse signed a cross-licensing agreement for the bar-winding-rotor design, later called the squirrel-cage rotor. Induction motor improvements flowing from these inventions and innovations were such that a 100 horsepower (HP) induction motor currently has the same mounting dimensions as a 7.5 HP motor in 1897.

Question: Who built the first induction motor?
Ans: Walter Baily


Article: In 1886, Woolwich munitions workers founded the club as Dial Square. In 1913, the club crossed the city to Arsenal Stadium in Highbury. They became Tottenham Hotspur's nearest club, commencing the North London derby. In 2006, they moved to the Emirates Stadium in nearby Holloway. Arsenal earned €435.5m in 2014–15, with the Emirates Stadium generating the highest revenue in world football. Based on social media activity from 2014–15, Arsenal's fanbase is the fifth largest in the world. Forbes estimates the club was worth $1.3 billion in 2015.

Question: When was Arsenal originally formed?
Ans: 1886


Article: In Terry v. Ohio (1968) the court divided seizure into two parts, the investigatory stop and arrest. The court further held that during an investigatory stop a police officer's search " [is] confined to what [is] minimally necessary to determine whether [a suspect] is armed, and the intrusion, which [is] made for the sole purpose of protecting himself and others nearby, [is] confined to ascertaining the presence of weapons" (U.S. Supreme Court). Before Terry, every police encounter constituted an arrest, giving the police officer the full range of search authority. Search authority during a Terry stop (investigatory stop) is limited to weapons only.

Question: What is an investigatory stop's search limited to?
Ans: what [is] minimally necessary to determine whether [a suspect] is armed


Article: Near New Haven there is the static inverter plant of the HVDC Cross Sound Cable. There are three PureCell Model 400 fuel cells placed in the city of New Haven—one at the New Haven Public Schools and newly constructed Roberto Clemente School, one at the mixed-use 360 State Street building, and one at City Hall. According to Giovanni Zinn of the city's Office of Sustainability, each fuel cell may save the city up to $1 million in energy costs over a decade. The fuel cells were provided by ClearEdge Power, formerly UTC Power.

Question: What company provided New Haven with the fuel cells currently in place throughout the city? 
Ans:
ClearEdge Power