| |||
| ring main system | |||
| primary series circuit | |||
| power circuit; main circuit; traction circuit | |||
|
circuit principal : 12 phrases in 8 subjects |
| Agriculture | 1 |
| Computers | 1 |
| Electrical engineering | 1 |
| Environment | 1 |
| General | 1 |
| Information technology | 1 |
| Nuclear physics | 1 |
| Transport | 5 |