| 361 / | HD | ELECTRICITY: ELECTRICAL SYSTEMS AND DEVICES |
| 271 | DF | ELECTROSTATIC CAPACITORS {4} |
| 277 | DF | .~ Variable {4} |
| 287 | DF | .~.~ Mechanically variable {5} |
| 292 | DF | .~.~.~ By varying effective area of electrode {6} |
| 298.1 | DF | .~.~.~.~ Rotary plates {5} |
| 298.5 | ![]() | .~.~.~.~.~ With adjustment means |