![How to make an electromagnet that changes its polarity after a fixed interval of time? | ResearchGate How to make an electromagnet that changes its polarity after a fixed interval of time? | ResearchGate](https://www.researchgate.net/profile/Sandesh-Saxena/post/How-to-make-an-electromagnet-that-changes-its-polarity-after-a-fixed-interval-of-time/attachment/59d622736cda7b8083a1c36f/AS%3A273593311662082%401442241136949/download/electromagnet.jpg)
How to make an electromagnet that changes its polarity after a fixed interval of time? | ResearchGate
![electromagnetism - Bar magnets side by side, opposite polarity, repulsion at null point? - Physics Stack Exchange electromagnetism - Bar magnets side by side, opposite polarity, repulsion at null point? - Physics Stack Exchange](https://i.stack.imgur.com/rDEKf.png)
electromagnetism - Bar magnets side by side, opposite polarity, repulsion at null point? - Physics Stack Exchange
If the polarity of the magnet is reversed from the north pole to the south pole, and brought furthermore near a coil, what happens to the direction of the induced current? Why? -
![A three-pole DC motor The commutators on the shaft change the polarity... | Download Scientific Diagram A three-pole DC motor The commutators on the shaft change the polarity... | Download Scientific Diagram](https://www.researchgate.net/publication/10999761/figure/fig4/AS:601691237916736@1520465778820/A-three-pole-DC-motor-The-commutators-on-the-shaft-change-the-polarity-of-stator-magnets.png)