A motor drives a display platform. Two programmes set the current direction during successive half-turns of the motor coil. The symbols + and − indicate opposite current directions.
| Half-turn | Programme A | Programme B |
|---|---|---|
| 1 | + | + |
| 2 | − | + |
| 3 | + | − |
| 4 | − | − |
Explain which programme will keep the platform rotating in the same direction.