Задание 2 к тексту Mains Frequency
Ответьте на следующие вопросы письменно:
► What is the mains frequency in the most part of the world?
► At what frequency a system with many transformers would be more economical?
► What causes the change in brightness and flicker of the incandescent lamp?
► Why commutator-type motors do not operate well on high-frequency AC?
► Is there a fixed relationship between the number of magnetic poles in the induction motor field, the frequency of the alternating current, and the rotation speed?
► Was direct-current power entirely displaced by alternating current?