# Why maxwell's 3rd equations has no coefficient?

1. Sep 21, 2014

### lowerlowerhk

For the four Maxwell equations, only the third one (Faraday's Law) has a proportionality coefficient of -1, while rest have a magnetic constant or electric constant .

It doesn't seem like the units of the third law are calibrated to eliminate the constant. So why is the coefficient equal to exactly -1, not some materially dependent coefficient k?

2. Sep 21, 2014

### jasonRF

3. Sep 21, 2014

### Staff: Mentor

I second jasonRFs comment. It is purely due to the units chosen.

4. Sep 22, 2014

### Meir Achuz

The real question is, why do the other 3 equations have dimensional constants introduced. That is because they use different units for E and B, even though they are parts of the same tensor.

5. Sep 22, 2014