One CGS emu of magnetic pole strength is that pole which, if placed 1 cm from a similar pole in vacuo, will repel it with a force of 1 dyne. The system is based on the proposition that there exists a...One CGS emu of magnetic pole strength is that pole which, if placed 1 cm from a similar pole in vacuo, will repel it with a force of 1 dyne. The system is based on the proposition that there exists a "pole" at each end of a magnet, and that point poles repel each other according to an inverse square law.