Read the text and answer the questions.
1. When did the age of electricity begin?
2. What was the invention of N. Tesla?
3. What does power engineering deal with?
4. How can you call the systems which are not connected to the grid?
5. Where are single-phase and three-phase electric powers used?
6. What is the aim of increasing voltage?
Ответьте на вопросы и вышлите ответ на проверку в виде файла.