Problem: Doubly fed electric motors have two independent multiphase winding sets, which contribute active (i.e., working) power to the energy conversion process, with at least one of the winding sets electronically controlled for variable speed operation. Two independent multiphase winding sets (i.e., dual armature) are the maximum provided in a single package without topology duplication. Doubly-fed electric motors are machines with an effective constant torque speed range that is twice synchronous speed for a given frequency of excitation. This is twice the constant torque speed range as singly-fed electric machines, which have only one active winding set.
What advanage do independent multiphase winding sets have?
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Answer: contribute active (i.e., working) power to the energy conversion process


Problem: Jerry Kurz also stepped down as commissioner of the AFL as he was promoted to be the AFL's first president. Former Foxwoods CEO Scott Butera was hired as his successor as commissioner.
What was Scott Butera's job title prior to becoming AFL commissioner?
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Answer: CEO


Problem: Lamps designed for different voltages have different luminous efficacy. For example, a 100-watt, 120-volt lamp will produce about 17.1 lumens per watt. A lamp with the same rated lifetime but designed for 230 V would produce only around 12.8 lumens per watt, and a similar lamp designed for 30 volts (train lighting) would produce as much as 19.8 lumens per watt. Lower voltage lamps have a thicker filament, for the same power rating. They can run hotter for the same lifetime before the filament evaporates.
What watt lamp can produce 17.3 lumens per watt?
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Answer:
unanswerable