0
votes
1answer
91 views

Magnetic Field and the Speed of Light

Is it just a historical choice that both magnetic field and the Lorentz force equation include the speed of light? I figure that whoever wrote up the equations (in cgs!) could have put both factors ...
3
votes
1answer
131 views

CGS Units for Magnetism

Why does the formula for magnetic field force include the speed of light in the denominator in cgs units? Where does the extra $c$ go in SI units?
0
votes
1answer
345 views

CGS Units to SI Units

This may be a stupid question but I am having trouble getting the same result in CGS units as I would if I used SI units for a unitless calculation. I have to calculate $E_c=\frac{m_e c\, ...
4
votes
3answers
174 views

What is the missing proportionality constant in the magnetic levitation formula?

The formula for magnetic levitation is $$ B \frac{dB}{dz} = \frac{ \rho g }{\chi} $$ but as always, I have a hard time figuring the units in SI. The left hand side is $\mathrm{T^2 /m}$, while $\chi$ ...
2
votes
1answer
188 views

Does the expression of the orbital magnetic dipole moment have $c$?

The orbital magnetic dipole moment of a particle with mass $m$ and charge $q$ can be shown to be related to the orbital angular momentum through the equation $$\displaystyle ...
4
votes
3answers
2k views

Coulomb's Law: why is $k = \dfrac{1}{4\pi\epsilon_0}$ [duplicate]

This was supposed to be a long question but something went wrong and everything I typed was lost. Here goes. Why is $k = \dfrac{1}{4\pi\epsilon_0}$ in Coulomb's law? Is this an experimental fact? ...
7
votes
1answer
344 views

Magnetic susceptibility in 1/eV

In this paper the authors refer to transverse susceptibility $\chi_{ \perp}$ [meV $^{−1}$] I was taught that the magnetic susceptibility is dimensionless. How do I get $\chi$ in the above ...