QUES: In 1886, Frank Julian Sprague invented the first practical DC motor, a non-sparking motor that maintained relatively constant speed under variable loads. Other Sprague electric inventions about this time greatly improved grid electric distribution (prior work done while employed by Thomas Edison), allowed power from electric motors to be returned to the electric grid, provided for electric distribution to trolleys via overhead wires and the trolley pole, and provided controls systems for electric operations. This allowed Sprague to use electric motors to invent the first electric trolley system in 188788 in Richmond VA, the electric elevator and control system in 1892, and the electric subway with independently powered centrally controlled cars, which were first installed in 1892 in Chicago by the South Side Elevated Railway where it became popularly known as the "L". Sprague's motor and related inventions led to an explosion of interest and use in electric motors for industry, while almost simultaneously another great inventor was developing its primary competitor, which would become much more widespread. The development of electric motors of acceptable efficiency was delayed for several decades by failure to recognize the extreme importance of a relatively small air gap between rotor and stator. Efficient designs have a comparatively small air gap. [a] The St. Louis motor, long used in classrooms to illustrate motor principles, is extremely inefficient for the same reason, as well as appearing nothing like a modern motor.
Who did Sprague work for early in his career?

ANS: Thomas Edison

QUES: The current I(t) through any component in an electric circuit is defined as the rate of flow of a charge Q(t) passing through it, but actual chargeselectronscannot pass through the dielectric layer of a capacitor. Rather, one electron accumulates on the negative plate for each one that leaves the positive plate, resulting in an electron depletion and consequent positive charge on one electrode that is equal and opposite to the accumulated negative charge on the other. Thus the charge on the electrodes is equal to the integral of the current as well as proportional to the voltage, as discussed above. As with any antiderivative, a constant of integration is added to represent the initial voltage V(t0). This is the integral form of the capacitor equation:
To what is the charge on the electrodes of a capacitor proportional to?

ANS: proportional to the voltage

QUES: The 45 rpm discs also came in a variety known as extended play (EP), which achieved up to 1015 minutes play at the expense of attenuating (and possibly compressing) the sound to reduce the width required by the groove. EP discs were cheaper to produce, and were used in cases where unit sales were likely to be more limited or to reissue LP albums on the smaller format for those people who had only 45 rpm players. LP albums could be purchased 1 EP at a time, with four items per EP, or in a boxed set with 3 EPs or 12 items. The large center hole on 45s allows for easier handling by jukebox mechanisms. EPs were generally discontinued by the late 1950s in the U.S. as three- and four-speed record players replaced the individual 45 players. One indication of the decline of the 45 rpm EP is that the last Columbia Records reissue of Frank Sinatra songs on 45 rpm EP records, called Frank Sinatra (Columbia B-2641) was issued on December 7, 1959. The EP lasted considerably longer in Europe, and was a popular format during the 1960s for recordings by artists such as Serge Gainsbourg and the Beatles.
What format was phased out by the end of the 1950s?

ANS: EPs

QUES: The Legend of Zelda: Twilight Princess is an action-adventure game focused on combat, exploration, and item collection. It uses the basic control scheme introduced in Ocarina of Time, including context-sensitive action buttons and L-targeting (Z-targeting on the Wii), a system that allows the player to keep Link's view focused on an enemy or important object while moving and attacking. Link can walk, run, and attack, and will automatically jump when running off of or reaching for a ledge.[c] Link uses a sword and shield in combat, complemented with secondary weapons and items, including a bow and arrows, a boomerang, bombs, and the Clawshot (similar to the Hookshot introduced earlier in the The Legend of Zelda series).[d] While L-targeting, projectile-based weapons can be fired at a target without the need for manual aiming.[c]
What 2 main weapons does Link use in combat?

ANS:
sword and shield