Question

Two electrons move parallel to each other wihth equal speed v the ratio of magnetic and electric force between them os

Answer 1

Two electrons move parallel to each other wihth equal speed v the ratio of magnetic and electric force between them is ...

from Coulomb's law,

force of repulsion acting on each electron, Fe = $\frac{1}{4\pi\epsilon_0}\frac{e^2}{r^2}$

where r is the seperation between electrons and e is charge on each electron.

again, magnetic force acting on each electron due to its motion, Fm = $\frac{\mu_0}{4\pi}\frac{e^2v^2}{r^2}$

so, Fe : Fm = $\mu_0\epsilon_0 v^2$

we know, $\mu_0\epsilon_0=\frac{1}{c^2}$, where c is speed of light in vaccum.

so, Fe : Fm = v²/c²